This is just my personal opinion, but that particular car doesn't get my blood flowing. While the price is excellent for the mileage, the SMG and color combo doesn't really cut it for me (plus you already have a Jerez Black).
The E46 is already a basketcase in terms of maintenance, so an MT would have to be an absolute must. Secondly, I'd go for a crazy color like Imola Red or LSB, although I realize that's not for everyone.
Personally, I'm deciding to skip the E46 M3 (had a regular one) due to reliability of S54.
Current: E92 M3 Sparkling Graphite/Bamboo Beige/6MT. E36 M3 Techno Violet/Dove/5MT. E85 Z4MR Alpine White/Imola Red/6MT