Why not try out the village of Cavtat which just down the coast from Dudbrovnik.
There are plenty of hotels and the one we stayed cost me 30 euros a night complete with a good parking space
A mate had pre-booked a apartment in Dubrovnik and had to leave his bike on a very busy street
Cavtat I think was brilliant as you can for about a tenner catch a boat right into the old town of Dubrovnik
It also has another advantage if you fancy flying as the town is only 15 mins from the airport (so I have been told) and some of the cheap airlines go there therefore its a cheap place to visit for the weekend
Peter