Cost only works on group buys you can no longer get, you're paying for exclusivity of the kit.

If you expect cost for readily available parts you're on crack. I'm not buying full price for used parts, including parts I may not want, for what I can buy them new. The only way this makes any sense is if you have some combination you can't get like a Ducky with Bobas and you had to desolder to put them in. Keep in mind, your target audience is really small at that point but at least you can justify it.

My advice, ask 80% what you paid and be willing to accept 60%.
I know some just clutched their pearls at that, but oh well, it's a USED, readily available keyboard. You lubed it, great, but it's not like that requires special tools or skills like desoldering does, you don't get paid for your labor on personal projects, that's just how it is. Also considering selling the board separate from the switches because you're limiting your audience.

it would be best to trade in my opinion. but if trading is not an option then at cost. board flipping a tofu isn't exactly worth it  )