air cond leak on 1996 Volvo 850

air cond. leak told upper lower hoses plus possible compressor leak price to repair?

Asked by for the 1996 Volvo 850
I've diagnosed many of these 850's for A/C leaks and can't remember seeing any of the hoses or the compressor leak very often, and especially not all at the same time. That's not to say some or all of these aren't leaking, but it's highly unlikely. My guess based on experience is that the evaporator is leaking.
After the system has been recharged, how long does it take for the refrigerant to leak out?