Every Sphinx I've seen was in near-mint condition, and there's not much to look for. Some of the full-size .40 models seem to have had problems, but I've never heard of a problem with the 9mm models.
Parts can be a problem -- and you'll have to deal directly with Sphinx in Switzerland with the older models. Sphinx cannot ship mags -- Swiss law considers a mag a 'restricted" item. Some parts are that way, too.
Most CZ factory mags will fit, as will most Mec-Gar mags, but you probably need to see if they'll fit in the mag well before you buy. (At gun show, etc.) Pro-Mags fit in my CZ Compacts, but wouldn't fit in my Sphinx Compact. (Pro-Mags for CZ compacts were a better deal than factory mags, price wise, with similar good function; about the only ProMags I recommend.)
The customer service folks at Sphinxarms can speak English, and are very helpful. Their website is www.sphinxarms.com
. You can ask questions at firstname.lastname@example.org
. My dealings with them have been limited, but they've been very helpful.
Most of the Sphinxs I've seen in the 2000 series, sell for $600 - $675, but you don't see a lot, so the price you paid may not be all that far out of line. Having one is a lot better than maybe getting one later, at a lower price.
If yours is a 2000P it is a compact, and you've got to be careful when buying magazines.
Here's a picture of mine (added later):