im in the UK, but i picked up this unit a few months back from a shop called B&Q ( equivelant to home depot in U.S i guess )

i was having the same problem, air conditioners in this country start at about £200 for cheap ones, i needed cool air but not at that price, in a small grow like mine air-con is probably overkill.

this thing is called an "air cooler" it cost £40-50 and is a good compormise between air con and just a fan.
its a stand alone unit about 2feet high and about a foot square.
in the top part there is a fan unit, and in the bottom, a resevoir of water.

there is towel that slowly rotates through the water , and past the fan, so air is blown through the wet towel cooling the air, and out the vents at the front of the unit.

this, in combination with a decent duct fan to pull air out of the room has solved all my heat/air circulation problems.....but my set up is only small with 1 hps light,.