Judging from his past comments and thoughts, it's less about the money and more about him trying to figure out if he can use this as a relatively easy career path. Obviously us readers can see what's going to happen once he's unleashed on normal dungeons with the full suite of metal slime upgrades, but he's just an unmotivated kid, and not even one shown to be particularly into gaming or anything else to use as something of a basis for this. And most of the seekers talk about selling stuff anyways over using them.honestly, that kinda shit really weirds me out. You get an opportunity to get a super power, why would your first instinct be to sell it for some quick cash? Invest it in yourself and use it to make money if you need it. He's a teenager at that, he doesn't actually need extra money right now so he should go straight away to improving his abilities so he can make money in the future. If you're going to sell it, only sell the repeats, don't sell stuff you don't have yet...
in the next chapter, he obtains the gigachad ore, comprised of a pure crystalline creatine-tren matrix
progress for the sake of progress with no goal on sight is pretty sadI kinda like this MC. He always complains, but he never stop moving forward.