A/C problem - fix or replace? Newbie

[44rman]

I accidently cut the "power cable" to my a/c condensor a few days ago. I was able to re-connect the wires, but since then my a/c unit has been making this loud buzzing noise. It is MUCH louder when the fan is actually blowing, and when it's off, it still makes a buzzing noise. This goes on pretty much all day. I called a repairman and described this problem to him and was quoted $350 to replace this "connecting" cable. This seems a bit high. I also inquired as to a whole new system and was told that if I was to purchase a 4 ton system, i would need to upgrade the A-coil on my furnace (something about it being 10 -SEER and needing a new 13-SEER(it think it's SEER) unit. He also mentioned something about a Txv(?)-Valve that needed to be replaced(this might be the 10-to-13 SEER upgrade he was talking about). I was quoted around $5500 for the job. I didn't really understand much of what he was saying and don't know what brand unit he was offering. Was the initial $350 quote too high? If it was, i'm assuming that any subsequent "deal" he was offering might also be bogus. I would think that replacing the A/C unit would just require replacing the a/c unit and leaving the furnace alone. My a/c unit is outside and the furnace is in the garage. Any help would be greatly appreciated!!!

[suprheat]

What does him replacing the cable do that you fixing it didn't? What is buzzing and how will replacing the cable make it stop? I find that HVAC techs more and more are charging outrageaous prices to repair in the the hopes, I suppose, of selling new equipment. The wiring replacement price is grossly out of line unless you have a situation that is beyond a normal installation. You shouldn't need a HVAC tech to repair the wiring if you want to call a regular electrician instead - the only prob with that though is the electrician won't be able to do any trouble analysis for you.

[dnpeters]

44rman - I can't help you with the buzzing, but I also recently got a quote on replacing my 30-year old system (furnace/AC, etc.). I was quoted $5800 for a 4-ton Rheem, from a dealer I've dealt with for many years and trust. Good luck.