Yes, I can relate to this sentiment (and it's not OT because it pertains to well-built Japanese amps). I've been spoilt by how much I've lucked out on the last 2 amps I've sold on. Made a profit on one, and only had about 30% depreciation for another (and this was an obscure handbuilt amp). The one I made profit on was a mid-90s Marantz Reference PM-17 (part of a series of equipment I firmly believe to be on the cusp of becoming classics; the swan song of Japanese conglomerate supremacy in sanely-priced amplification). It is more beefy than comparable amps in Marantz's recent lineup. I think it looks a hell lot better (trust me, I own a PM6004), is built a ton better and looks more timeless than Marantz's current stuff (picture not of mine, but similar amp):
I paid the equivalent of $250 for it used from it's second owner. It later received an overhaul (recap, new toroid) from the official Japan-trained Marantz tech in the country. He quoted $60. He later realised the new parts he'd shipped in/taken from the spare stock cost much more, even excluding his labour. He honoured his original quote. I was about $310 in on the amp. Used it for nearly 2 years, and sold it for
a profit at $420.
I got paid for using an amp with strong manufacturer support and was an utter pleasure to use (the chamfered knob with a weighty but smooth action is a dream) after routine maintenance. Let that sink in. I only sold it on because the idiot of a first owner bought in on the bi-wiring snake oil and got a third-party tech to
drill holes in the back panel for a second pair of binding posts. The tech used crappy ratty plastic-nickel ones like you'd find from Radioshack, unlike the knurled brass of the factory posts. Probably only an aesthetic thing, since the Marantz tech passed it, but still a total eyesore I couldn't tolerate. And it still turned a profit.