I have a 97 Civic LX 4D, The A/C was working fine since the last 2 years but I had parked it for 3 months in winter without using it and ever since it doesnt work at all. I suspect the gas leaked out but how does one check for a leak without paying a fortune?

Are there any tell tale signs? I can smell some weird gas when I switch it on now and the compressor does kick in......

What is a good price to get it refilled?