These tents are all the rave but I'm old school... I have a 3 x 3 veg room (which actually had to be forced into use as a flowering room now) all you need are the following.
6 (be safe 7) 8' untreated 2 x 4's
box of wood screws
some 90 degree brackets ( get 20 and take some back)
white plastic or mylar sheets
Sorry I don't have pics as it's in use and wrapped in plastic
cut 10 3' length pieces from 2 x 4. 4 will be your base, 4 will be your top, 1 will go across the top (to hang your hooks) and one will go across the middle to mount fans and anything else.
Simple, the 2 x 4's should cost about $2 each ($14) box of screws $7 but if your hardware store sells screws by the lb you only need about 50. brackets are like .70 each ($14) white plastic isn't bad in price probably around $15 - $20
There you go $50 tent, easy to setup and quick to tear down if need be.... bonus shipping cost is your gas.