The 2270 seems to be a "hot favorite" on "that auction site", probably in large part due to another site with a lot of reviews of it (favorable ones, of course!). The review site doesn't review the 2265/B, 2275, 2285/B, etc...(except for a few mentions UNDER the heading of the 2270!) though, which are also great-sounding units. I'm just speculating on the reason, but something seems to have given the 2270 a "special boost" on its price. If you can get one cheap, then grab it, but otherwise I'd suggest looking at the less-popular models that will probably give you similarly good sound for less money. I can't say that from first-hand knowledge, as I don't have a 2270, but I do have the 2275 and 2285B, as well as a number of lower-powered models. I don't think any one of them has an even remotely disappointing sound, not even the lowly 2215; just some models are a little bit sweeter-sounding than others.
The lower-powered ones in the series that are particularly favored seem to be the 2216B, 2220, 2230, 2238B (perhaps the 2245, also) --but probably every model in the series has its fans. You can't go too far wrong with any of them.
The "B" models tend to be improved versions that corrected problems or weaknesses in earlier (non-B) models and also incorporated improvements made in designs/technologies, so they are probably preferable. They seem to sell for a little more than their non-B predecessors, too. Opinions vary on which look best, though; some prefer non-B's; others prefer B-types.