A snorkel set you buy for $50 may be a waste of money if you're soon going to get better stuff for diving, especially if $50 includes fins.
Is there a reason your uncle is waiting until after you finishing your cert? Because you will generally need this gear to take the certification class. The snorkel doesn't matter much as long as it's not too bulky, as you don't use it much when diving. But inexpensive snorkeling fins usually aren't suitable for diving because you're pushing more stuff through the water and are more likely to find yourself in a situation where you need more power sometimes. And your mask at a minimum needs to be tempered glass and fit very well for diving, as well as allow you to pinch your nose easily. (It's obviously best if your mask fits well for snorkeling too, but it's not quite as critical as for diving.)
Maybe you can make a deal with your uncle to take you shopping now, you throw in your $50 and he pays the rest? Especially if he is a diver and can help you buy the right stuff.
If you still really want to get an inexpensive set, I would suggest just going to a sporting goods store or anyplace that sells this stuff. You should have lots of choices where you are. It's hard to suggest a specific set, since the most important thing is that the stuff fits and there's no way to know what will fit you. Try on the masks to get a good fit. Here is some information on getting a mask that fits right -
http://www.scubaboard.com/forums/fins-masks-snorkels/273886-mask-fitting-procedure.html. Some inexpensive sets come in packaging that makes this impossible, I would avoid those. A suitable mask doesn't have to be expensive though, if you're lucky you will find something that fits well that you can use diving or have as a spare. Also try on fins to see if they feel comfortable and won't give you blisters.
