Cheaper the board the more likely it is to break. Simple economics. Quality and cheap are never really synonymous, you get what you pay for. Depending on where you live you may be better off with a longboard rather than a traditional skateboard, but I've never owned one and can't say for sure if they're any more sturdy than a traditional board...
Then again its been about 15-20 years since I rode so I could be wrong on all fronts. Also, from personal experience, I varied between 145 and 175 (yeah I know) in the years I rode and I've snapped plenty of boards at all different weight classes, so its not necessarily about weight so much as how you land a trick (or bust your ass).
Its not something to take lightly, if you're really interested in it be prepared to spend some money on it constantly because no matter what happens, at some point you will break a board. And you're just going to have to get another and keep going if you really want to learn.
I've seen some heavyset dudes skate before so its not a matter of weight anyway, its just a matter of what style you're going for and how willing you are to accept that you're probably going to bust a few along the way. I've had trucks snap because of metal fatigue or poor craftsmanship, or something stupid I was attempting, as well as boards split... I ultimately quit because while I loved it, I didn't love the injuries that came about from doing it, compiled with older injuries from other sports in my youth and stupid crap I did as a teenager/20 year old, and the few months I spent doing independent wrestling before I nearly got killed by a bad spot.
