Way too expensive. Tube upgrades generally don't add much value to a sale. Better to sell the tubes off separate, and drop the price of the amp. No word on how many hours those tubes have on them-- and they're not exactly top-flight WA-5 tubes. PSVane 300B, National drivers, and it looks like Sophia Princess rectifiers-- though I thought the Sophia had a white base? Anyway, an upgrade, but not by much.
Better to go back to the stock tubes and sell it at $2200ish. I think that one will sit there for a while.
The way I read the listing is that the amp has the upgraded caps in addition to the average tubes you've mentioned. The cap upgrade is like $1200 from Jack these days, in which case the price would not be so bad.