How much will it cost me?

I have a 93' Honda Civic EX and the a/c turns on but no cool air blows out, no heat either. Auto shops don't sell 93' compatible Freon for my car, I already tried. How much will it cost me to repair the A/C or to put in a whole brand new one compatible with the Freon they have at auto stores?

You said heater doesn't work also so its more then just Freon. Could be from about $100 to about $1000, depending on the real problem. Is your fan running? Sounds like maybe you have a bad AC/heater switch, sounds like a good place to start looking.

A few hundred bucks

If your '93 uses R-12 and it is just low go to a auto shop and buy the conversion kt. All it consist of are adapters that screw onto the high and low ports. Then just put R-134 in it and it should cool. They tell you the two are not compatible but I have done this before and it works.