I've sold a bunch of stuff I really liked. I regretted it for awhile, sometimes that regret fades, other times I wish I could have something back. Overall, I'm happy where I landed in terms of what equipment I have now. Heck, I'm doing that right now. I'm selling my Aragon 8008X3, which I happen to really like and enjoy, but here I am listing it for sale.
If you have something in mind that you definitely want, I would say go for it. If you can get the price you want, awesome. If you can't, don't compromise. Either way, you'll either have the amp you already own and enjoy or you get your asking price and then you can get that other thing you want.