Bloodstained: Ritual of the Night

After playing the game naturally for a while you should amass a lot of equipment. Save you game and sell it all. Did you get the achievement? Yes? Great! Now reload and carry on scott-free.
You didn't get the achievement? Then see how close you got and work out what you need to make up the deficit. Do what you have to do to earn that money then repeat.

First you need to the shard alchemical bounty from the demon 019 Zagan, bull with wings. Raising the rank will increase the chances of crafting 2 or even 3 items with Johannes. It will cost you Alkahest to dismantle your item, but you will counter that cost with what you’re selling. So what you do is create an expensive piece of equipment for the price of two. At the point where I am in the game, I would make a two hander sword call Schedar. You need a crystal, ice ring, and a two handed sword called Gram. If it doesn’t double, just dismantle and try again. In theory, you can just rinse and repeat without fear of truely losing any materials. This solution should work with the gilded youth achievement as well.