I don't want to alarm you or stop you from getting a "B" by any means, they are awesome cars and they are pretty easy to work on, parts are readily available at reasonable prices (kind of like our CB 4's) but they are all old, the last production year was 1978. Pre 1974 are the most desireable, these are the chrome bumper years but the rubber bumper years can be converted if so desired. I could go on and on.....
The picture I posted earlier was a "before" picture, pretty much as I bought it. Looks good from far but is far from good. Like I said, the sills are notorious for rotting from the inside out. The sills are the backbone of the car, they are made up of 4 sheet metal pieces spot welded together. The picture below is what I uncovered after cutting off the outer sill piece of the same car. In this you can see the middle piece of the sill with many holes. The next picture is the inner sill, lots of rust.
There are lots of really nice MGB's out there. One old saying is "you will pay $6000 one way or another, if you buy a $3000 MG you will put $3000 into it". Learning to weld is one of the things that comes in handy with a LBC (Little British Car). Again I'd be more than happy to assist in any way.
Good luck! Safety Fast (it's the MG logo)