I'd try to part out , as others have said. I'd also push for more for your trade in.
I drove an RS5 a few years back with the sport exhaust. On the track,for an almost 4,000lb car, it was simply incredible. I loved it. Would be an amazing DD. I actually had more fun driving it than the R8 V8 with the old single clutch trans.
If you want help with negotiating or anything, let me know. also, look a few hundred miles (or more) out, to broaden your search parameters.
Re: Audicare - I got it on the A3 and it was only like $650. It varies by model.. check all the services and make sure its actually worth it... you should at minimum get a brake fluid flush (or two), coilpacks and plugs at some interval, cabin filters, DSG flush/change, and then a handful of oil changes.