Any "PNEU SERVIS"( TYRE SERVICE) will be happy to fit you up with a suitable set of winter tyres.Winter Tyres are not compulsory (unlike year-round switched on headlights)but are probably a very good idea especially out of town.
Price wise as with everything else it's best to shop around (inc.internet) obviously if you buy separate the fitters will charge for their services (and maybe even if you buy from them!).
It can be a bit of a problem this time of year getting an appointment for fitting as it is the busy period and everybody leaves it to the last minute.Anyway it hasn't started snowing yet!
Another thing to think about is storage space for the other set of tyres until next spring.
The "PNEU SERVIS" at the top of Merhautova at the end of the 5 tram is reasonable and reliable but there are plenty to choose from.

Bet everybody's glad they got those winter tyres now!