try:
Wohnungen, Immobilien und Häuser bei ImmobilienScout24 mieten, kaufen, inserieren
site is in german language, but should be doable...
The listings are pretty accurate and up to date.
In general, appartments & houses r pretty cheap compared to other places in europe.
Lookup for city of Leipzig (or if nightlife is not important, but cost are, try Schkeuditz )
good luck!