New Air Handler and Condenser--what is a fair price

We have a Carrier 15 ton rooftop unit with the air handler on the first floor (3 story building) All pneumatic controls which someone made a mess out of before I started here. Ok, I'm able to get the AC to come on manually and shut it off with the breaker. This has been working fine for a few weeks and now they are asking for some kind of temp control. Is it possible to put a line voltage thermostat on the primary side of the transformer (280V)? If not, is it possible to break a connection anywhere that would give some kind of control? Thanks, Joe ps~reason for this is company trying to same money. ha!

Hi, So upset at myself for causing this accident. :wall: Anyway, was drilling a hole next to the AC lines and cut a hole on this copper pipe that(thinner of the 2) that goes to the York(central air) compressor. Of course, freon leaked out and is probably empty now. How much do you think it will cost me to get this repaired. The hole is a visible 1/4 to 1/3 of the 3/8"(approx) copper line. Should I even venture to patch the pipe and recharge it myself? I'm in Central, NJ. model H3RA060506G thanks.