"Used X. great shape, super deal. needs new remote, but you can get one pretty easy online."
What a load of crap. Take note, kids, I've had to replace a few remote controls during my years as an audiophile, and the process is neither cheap, nor easy.
Your best bet is really to dump the unit onto the secondary markey, and upgrade. Not only will you save the aggravation and cost of tracking down a replacement, shipping it, and waiting breathlessly to use the features of your oh-so-expensive gadget, but you'll have a new toy to play with while you wait for the old one to sell.
Point the second. If you are buying a stereo, buy it new. Every time. Because even though you find that perfect component, the one that was made to go with all the rest of your components, it's not a good deal unless you are prepared to just give your money away. If you get last year's model, next year's will be better.
That having been said, I'm also a cheap bastard. Buy it new, but don't pay retail. Shop. A lot. See if you can wait a month, two months, or even a year. Get yourself a good, multifunction remote, and just suffer along until you can find the real one at a bargain. Not only will you be able to use that expensive lump of plastic, but the remote you just bought will operate the next "bargain" you pick up. At least, it should.
My advice is to find what you like, and maintain it with simple cleaning, and easy use. If you must buy a used receiver, get the newest used model you can that has the features you want, then offer 1/4 of the retail price. Paying anywhere near the "original" cost (the real one, available about 2 months after release) is just a waste of money. Stereos, like automobiles, lose most of their value within the first 15 minutes of use. Plus, the odds are high that the seller really just wants it gone, to make more room for his new component.