There is no way to know what its going to cost without knowing whats wrong. As for r134 costing $14 a can, what size can? I can get it a WAl-Mart for less then $5. You first need to see whats wrong and if you have some decent abilities, you can do it yourself with minimal investment in tools. You can get an untraviolet dye that you add to your A/C system that will show where your leaks are, then you can start by fixing those. When your done there, you can put a vacuum to it and see if it holds and if so, then recharge it. Just do some research about A/C systems and once you understand whats involved, its easy to swap parts.