I have a 4 x 4 x 7 sunhut silver xl. I got it off ebay for around $215 shipped. Aside from one of the assembly pieces being mis-shapen (replacement was sent right out), it has been working good for me. In the past, people have reported toxicity issues but those were mostly the older version white tents...silver seems to be safe across the brand board.
The first thing to figure out is how big of a tent you need. Then you should bargain hunt, while keeping brand names in mind. I've read alot of good things about secret jardin and grow labs. (they may be the same company.) Good luck.