Yeah, I don't think it's the fact that you didn't spend enough money on a wheelset. You just didn't spend the time to take it to a shop and make sure the spokes were tensioned right.
Trust me, I'm a part time working college student, and I fully understand your decision to buy cheaper wheels. It's just that whenever you get a machine assembled wheel, you gotta be careful. If I got them, I would have at least shown in to my mechanic friend.
Don't let anyone tell you that your equipment sucks if it isn't expensive or top of the line. It's all about maintenance. Sometimes when it is cheaper however, you need to spend some more time on it.