I would say if you have the space in your house keep the Jolida 502 integrated you have. How old is it? The Jolida 502P I have from a couple of years ago is the amp section of the Jolida 502CRC Integrated and it can handle Tung Sol 150 tubes. With those tubes in your Jolida you can handle lots of speakers out there.
Regarding the sale value you will take it on the chin if you try to sell it. I've seen some Jolida 502 series amps used go for under $700 which is a steal IMO. You can try various sites like Craigslist but I just have mixed results selling audio gear on there. Lots of flakes, spam and the usual lowballers.
I keep spare amps to just mix things up and should an amp go which has happened I'll always have something to keep my speakers singing.
Regarding the sale value you will take it on the chin if you try to sell it. I've seen some Jolida 502 series amps used go for under $700 which is a steal IMO. You can try various sites like Craigslist but I just have mixed results selling audio gear on there. Lots of flakes, spam and the usual lowballers.
I keep spare amps to just mix things up and should an amp go which has happened I'll always have something to keep my speakers singing.