The salaries quoted are what you get from the NHS (national health service) which is government funded. If you are in a speciality where you can do private work as well (especially things like plastic surgery...) then the salaries can go up. I know of a couple of cardiothoracic surgeons who earn just over ?200,000 which isn't so dusty! I think most surgeons would average out at about ?130,000 pa. Also, depending on speciality, there is less on call work at wierd hours of the day as you move up the ladder, so you end up working shorter hours (albeit not much shorter...)
As for Southampton, I used to live there, and it's a great city to live in, and convenient for London too. Go for it! (the only reason I didn't apply there for med was because of someone I know there...)
MCAT scores - so long as they're not dismal, you have a chance as far as I can see. At degree level, you're expected to get at least a 2:1. Remember, most med students in the UK go straight from school, so they won't have done degree level work at all, so you're kind of at an advantage there.
It will cost more than a UK student pays. I know in the clinical years (yrs 3, 4 and 5) you have to pay something like ?16500 pa. It's quite a bit less for yrs 1 and 2, although with more integration that might change.
I'm writing too much! Bye
Fiona