[Catamax944]

There are large differences in market price from country to country in europe so it's a bit difficult to determine a good estimate for your country.
Based on what you said i would put it at around 2.5k euro and be prepared to negotiate a little.
A friend of mine in Italy recently sold a two tone 924 in pristine condition for 2.5k when upper market asking price is about 4k for base 924's but even if asking price is high in Italy i know for a fact that the market for these type of cars is dead still at this moment so if you really want to sell you have to price it at less than half of what it would be worth.
These are the going prices in Italy for good transaxle porsches
924 2k-4k
931 4k-7k
944 4k-7k
944S 4k-7k
944S2 8k-10k
S2 cabrio 8k-13k
951 8k-12k

It depends very much on your own country's market .