Marcy,Sorry to hear about your speaker problem. I had a front speaker go in my Passat, and the VW replacement speaker alone was $280 (covered under warranty). So, based on that, it makes me think that the speaker shop you visited would be replacing your rear speakers with non-VW speakers. This isn't necessarily bad, but it may not be the cheapest fix.
Do you still have a standard radio system? If so, you might call a local VW independent mechanic (or even the dealer) and ask if he can install a speaker from a salvage yard or a generic brand VW-compatible speaker at reduced cost. This way you're paying for just the one speaker that is damaged, and the replacement speaker will match the "sound" of the rest of your speakers.
While it isn't the hardest thing I've ever done, taking off the door panel and removing the speaker would not be something I would recommend to anyone who does not regularly do that type of thing. On our cars, the speakers are riveted in (rather than screwed in), making them even harder for do-it-yourself repair.
If you currently have your original VW radio and speakers, I would ask some questions before having someone work on your radio system (such as Best Buy, Circuit City, etc.)
I know very little about sound systems, but I believe that the factory system on Passats has an unusual ohm-rating or something like that, making finding a replacement speaker a bit more difficult. Anyway, my point is that you will want someone to fix it who is familiar with VW wiring so you won't get a weird sounding replacement speaker system.
If you don't find a mechanic who is helpful, I've had luck calling a few local audio shops (smaller places) and asking them if they're familiar with VW systems before having the work done. The folks at Best Buy & Circuit City aren't all bad, but they do have a bad reputation around here for not knowing the specifics about our vehicles and possibly messing things up even more.
Good luck!
-Stephen
Modified by macaddiict at 4:42 PM 5-30-2008
,
Stephen