1997 bmw 540i

I was wondering if any 1997 540i owners could help me out. I have the oppurtunity to pruchase a 1997 540i, 6-spd manual. It has a few dinan mods. Dinan stage 1 engine software, dinan rear exhaust w/ no resonator and intake. The car has 216,000 miles on it. Car also has 2002 17" staggard wheels. The asking price is $7500. Any thoughts? Price right? It has sort pckg. Any thoughts? Do these upgrades boost hp that much. any help is much appreciated. I don't really know a whole lot about BMWs.

thanks