That eBay listing suffers from what some of us call the Marantz tax. Their vintage components are a "thing" right now, and you can't even find a used one in poor condition for under a few bills. I tried helping a buddy find a 2270 but gave up since prices were escalating rapidly up near the four figure mark. (They were in the $700+ range when I looked a few years ago, and have continued escalating.)
The sad part is that despite this eBay 2230 being cosmetically perfect, the capacitors inside, never having been used, have been sitting for decades and likely will be far out of value. This unit will need a full refurbishing before it is even turned on. (Of course, some fool will buy it, plug it in, then be upset when a fuse pops or smoke comes out of the top--that is a risk with any vintage device that has sat unused.)
I've seen some of the rare black face Marantz from that era. When put in a nicely finished wood cabinet, they are striking.
I agree--that unit is too nice to let it go up in smoke (hopefully not literally!). The seller may not know better, but I would have advised in the listing for the buyer to have it professionally checked out before putting it into use. They can be brought up slowly on a variac to let the capacitors "reform" themselves but even so, electrolytic capacitors tend to have a lifespan of about 20 years, give or take a few years, before their values drift or they become unstable to operate.
The Marantz receivers from that era are keepers! Well built, with a sound quality that eclipsed their original price point. It's just a shame that they've become a fad and the prices have escalated so much--it's great for owners who want to sell, but it's hard for others to get into one of them without paying a small fortune for one. Much as I'd enjoy one in a smaller system, I'd wait until prices calmed down before I would attempt it.
Those old monster Pioneer receivers also fetch a lot of money these days. They're good also, but the Marantz has something extra...
There's multiple phases to Marantz. For me, the only true Marantz receiver which was made with Saul Marantz and Sidney Smith circuit designs and USA made, was the Model 18. Your old Marantz Receiver is a Marantz Japan unit which was 100% Superscope built, then there's Philips, then D&M Holdings, lastly Sound United new gear which bears the name.