When it comes down to it, you get what you pay for.

I wouldn't incubate anything I cared very much about in a zoomed incubator. If you've got a normal x normal clutch and you don't have any emotional attachment to the eggs, then why not give it a shot?

To be honest though, I wouldn't be surprised if the guy who's selling it has figured out that it's a piece of junk and is now doing his best to get rid of it. If you plan on keeping the thing and using it later, I'd recommend you just build your own incubator.

I built mine out of a rockstar energy drink display fridge that I got off of craigslist for $60, a basic herpstat and some heat cable. All together it probably cost me about $150 and I expect to get a lot of use out of it. :-)