Hi Sean,
I just bought my first maser last week. I was also debating the same questions 3200 vs 4200.
From what I gathered the 4200 would be the more sensible choice, as it should be more reliable and refined than a 3200.
However in the end I choose the 3200, mainly because of the rear lights and turbo's.
I cant tell you much about running costs as I have just bought it, however it looks like i do need to make some repairs to it already!!
Its worth getting it inspected first so you know what needs doing to it.
Also if you can do some work yourself then I think it won’t be too expensive. I plan to do as much as possible myself.
Good luck with the hunt.
Dan