No idea what I should ask for or accept for this. Spectrum Potion. Rarity 99.

You can easily check most item prices with the user shop search. The Spectrum Potion currently goes for around 10.8mil sP as you can see.

That's strange, because when I searched it the other day none showed up. Maybe I'm having trouble with my Java blocker again. Thanks!

That's strange indeed but things like that can happen. Glad I could help!