Weider plates

I have a standard weight set from Weider (about 16 plates, various weights, total of about 280lbs), and I have a question.  Since I haven't put too much money into the set, should I look to sell it and go for a good 300lb Olympic set?  Now that I am seriously addicted to weight lifting, I want something that will last me a while.  I also have found quite a bit of negative reviews on Weider's plates.
 
I want to make a decision before I purchase more weight, so any advice would be greatly appreciated.
 
Thanks!