What are you going to do with the plane after the rating? Keep it? Sell it?
To answer your original Q, I'd get an already certified/equipped 152. MX is a headache, why not avoid that quagmire?
However............................
I might suggest a certified 172. You may need the room for the extra charts, plates, wx briefs, and a little leeway on the size of the instructor/examiner
The 152 is going to be slow, giving you a lot of time to brief (and fly) the approach. It may be better to get something faster so that you are faster. You're spending less time, your brain works better, and the controllers are'nt rolling their eyes when they hear your call sign.
If you're trying to do this on the cheap - you get what you pay for, plus aviation ain't cheap.
I'm not sure you're going to get a good upgrade cost here since there are too many variables.
73M -