I advise people to use bagseed, especially beginners or people without a lot of money. Hell, take seeds from some average pot and it'll come out nice. I'm been surprised over and over again by what comes out of a grow when I just used bagseed (I tell my friends to save me some seeds from decent or better stuff, and I'll hit 'em back with buds later).
Then, what really excites me is the breeding that one can do with mystery bag seed. Select some plants that you like, get some more seeds..rinse and repeat. For me, its been worth it to save money from seeds and put it into lights. It's amazing what bagseed can do with some love and attention.