If you’ve spent even 10 hours running around Borderlands 4’s chaotic open worlds, you’ve probably got a stack of glowing purple eridium burning a hole in your vault hunter’s pocket. It drops from bosses, hidden chests, and even random environmental craters left by asteroid strikes, but far too many players waste their hard-earned stock on low-value purchases that don’t move the needle for their build. I can’t tell you how many times I’ve had a co-op partner complain they had no eridium for a raid entry, just because they blew 800 on a silly Claptrap skin the day before. If you’ve been asking yourself borderlands 4 where to spend eridium for the biggest long-term gains, you’re in the right place. I’ve put 120+ hours into the game across four different character classes, and I’ve tested every possible eridium vendor and purchase option to cut out the junk and highlight only the best uses.
Priority Eridium Purchases for New Vault Hunters
If you’re still leveling up and haven’t hit the level cap yet, your eridium spending priorities are way different than endgame players. The first thing you should dump every spare piece of eridium into is permanent inventory upgrades from the Crazy Earl kiosk in your main hub. Extra backpack slots let you carry more loot between fast travel stops, so you don’t have to leave rare legendaries behind because you ran out of space mid-mission. Bank slots are just as valuable, especially if you like to swap between multiple builds for the same character.
Next, if you get a legendary weapon that fits your playstyle before level 30, it’s worth spending 50-100 eridium on rerolling its anointment slot to match your class’ signature skill. For example, if you’re playing Zane, rolling an anointment that gives you 30% extra damage while your digi-clone is active will make even an early legendary viable for 10+ levels, which saves you from having to swap weapons every two hours.
You don’t need to hoard every piece of eridium you find as a new player, but you should hold off on any purely cosmetic purchases until you’ve maxed out your inventory slots first. It’s a small tradeoff that will make your entire playthrough way less frustrating.
Borderlands 4 Where to Spend Eridium for Endgame Build Progression
Once you hit the level cap and start chasing perfect builds, eridium becomes one of the most valuable resources in the game. The single best use for your stock at this stage is legendary weapon rerolls at the upgraded Crazy Earl kiosk. Unlike earlier in the game, you can reroll both anointments and individual weapon parts here, which is the fastest way to get a perfect roll for your build. For example, if you’re running a Moze splash damage build, rerolling a Vladof rocket launcher to get 120% splash damage and an anointment that boosts rocket damage while Iron Bear is active will cut your boss clear times in half.
Another high-value use is paying for access to secret raid encounters scattered across the game’s post-game maps. Most of these raids cost 250 eridium per entry, but they drop exclusive legendary weapons and class mods that you can’t get anywhere else. If you play with a full co-op team, you can even split the entry cost between all four players, so each person only pays 62 eridium per run. That’s a hack most players don’t find out about until they’re dozens of hours into endgame content.
You should also spend eridium rerolling stats on class mods and artifacts if you’re stuck grinding for a perfect roll. These items have way more random stat combinations than weapons, so spending 200 eridium to get the +skill points and damage boosts you need is way more efficient than spending 10 hours farming the same boss over and over for a drop that might not even have the right stats.
Low-Value Eridium Purchases to Avoid Whenever Possible
Not every eridium purchase is worth your hard-earned purple rocks, and there are a handful of options that are almost always a waste of money, no matter what stage of the game you’re in. I’ve wasted hundreds of eridium on these myself, so I’m saving you the trouble of making the same mistakes:
- Cosmetic skins and emotes: They don’t impact gameplay at all, and you can unlock dozens of them for free just by completing side quests and leveling up. Save these for when you’ve already bought every other high-value upgrade you need, and you have extra eridium to burn.
- Common and rare gear from roadside eridium vendors: These drops are always 5-10 levels below your current gear if you’re playing through the campaign, and they cost 2-3 times more than equivalent gear you can find just looting chests in the world.
- Temporary buffs from nomad vendors: The 10% damage boost or 15% shield regen buff you get for 30 minutes isn’t worth 100 eridium, especially when you can get the same buff for free by popping a combat pill you find in random loot crates.
I know it’s tempting to buy that funny vault hunter dance emote when you first see it at a vendor, but holding off until you’ve maxed out your inventory slots and got your core build gear will save you hours of grinding for eridium later. I made that mistake early on, and I had to spend two full afternoons farming eridium just to get enough to buy extra backpack slots when I hit level 30.
How to Stretch Your Eridium Stock Further
Even if you’re smart about your purchases, eridium can still run low fast when you’re rerolling gear for endgame builds. There are a few easy tricks to make your stock go twice as far without having to spend all day farming. First, prioritize eridium farming during double eridium events that run every two weeks on average. During these events, you get 2x eridium from all boss kills and chests, and 3x eridium from raid completion rewards. I usually save all my rerolling and raid runs for these windows to get the most value for my eridium.
Another easy trick is to sell any duplicate eridium-exclusive cosmetics you get from loot chests. Most players don’t realize you can get 50-100 eridium back per duplicate skin or emote, and if you play a lot, those duplicates add up fast. I’ve gotten almost 2,000 eridium this way over the course of my playthrough, just from selling skins I already owned.
Finally, only reroll gear when you have at least 1000 eridium saved. Rerolls are completely random, and there’s a chance you’ll roll a worse stat than the one you started with on your first try. Having a buffer of extra eridium means you don’t have to stop halfway through rerolling a weapon just because you ran out of stock, and you won’t end up stuck with a worse roll than you started with.
At the end of the day, the best answer for borderlands 4 where to spend eridium depends on where you are in the game. New players should focus on permanent upgrades first, endgame players should put their stock into perfecting their build and accessing exclusive content, and everyone should skip the low-value fluff until they’ve covered their bases. You don’t have to hoard every piece of eridium you find, but being intentional about your purchases will make your playthrough way smoother, and save you a ton of unnecessary grinding. If you test out these tips, you’ll never find yourself stuck short on eridium when you need it most.