For a 144k mile car...VERY pricy.....imo...have you looked online to see what the calculators consider "fair" average $$?
Look at it this way...
If you say a mini is good for about 200k (many are junk closer to 175...some go 220-250)...you are paying big $$ for the most expensive, least relilable miles left in that car....
If you buy that car...then need 2000$ for a clutch and/or head+Valve job....makes a very $$ car...

 

Are you really considering a base with 144k for anything over 3k?

I got my 03 R53 for just over 5000 from a dealer! sure it has some problems (wheel bearing, clutch noise which is normal for R53's and some other small things)
But it only had 100k on it when i got it..

I would look keep looking to find a 05-06 R53 with 70k~ miles for around $8k..

Remember to use KBB, there is no reason why any car should be more than 10% of the kbb price..