I'm in a very similar situation myself. I have more or less decided on the R53. Though I'm trying to figure out a good price point to look for. There is one in my town, 05 66k miles for 13000$. I offered 11000 for it, not sure what they are going for. KBB has it listed for around 10000...

 

I have 2006 R52, Koni FSD, Poly Lower control arm bushing, tower brace, and lower brace. Car is solid, goes straight when encountering potholes, patchy pavement or ruts. With FSDs, you can hit potholes, RR tracks at speed without rattling your teeth. Smooth and reasonably low NVH - perfect for trips.

Mileage is 25 city and 28 hwy. I frankly do not believe those who claim much over 30 MPG going 70 -75 MPH. (I have heard convertibles take more gas due to less being aerodynamic) You have to ignore the computer, check your odometer for accuracy against measured distances, and actually divide actual miles driven by gallons purchased.

197 WHP and 177 TQ. No engine work other than bolt-ons such as pulley, intercooler, CAI and catback and recent RMW custom dyno tune.

Bottom line, to me the R53 properly set up is the perfect handling exciting-to-drive street car.

 

that car was relisted twice, still available apparently. if you're into a performance R53 this has got to be the best example out there.

 

Sorry for not updating my OP. But been paying off my A4 more and I'm getting close to selling it. Looked at other MINIs and so far I'm inclined towards the R53 or maybe R50. Forget fuel economy

Anyways, found something interesting and might be a good (or not) project car

http://boston.craigslist.org/gbs/cto/3741805808.html

Disclaimers:
The good:

New clutch <10k miles
Rebuilt supercharger <10k miles
Body and interior good
140K miles, mostly highway
Full size spare
Extra set of wheels for winter tires

The bad:
Needs shocks/struts
Dead Battery
Needs two tires
Needs rotors and pads (from sitting)

Do you think it's worth the gamble. New clutch and rebuilt supercharger recently mean I don't need to worry about it.

Needing new shocks/struts means I can put in Koni FSDs or similar.

Whatdya think?