My ac unit is leaking from somewhere inside the unit because after the unit runs for a period there is water slowly coming out onto the floor and I was wondering what could be leaking from the inside, we had freon put in last summer.How much does it usually cost to have this checked (just an estimate).

Most likely your condensate drain is plugged,it's a pretty easy fix. Not sure where you are located but,in southern Illinois the going rate is about 70 bucks an hour.

Trying to get estimates here is a lost cause. Without being there to see the actuall problem and not knowing prices in your area etc etc. But, Im assuming you are talking about water around your furnace? Make sure drain line that comes off ac coil is not plugged. You may also have a cracked or rusted out drain pan. I will say that this could be an easy fix, that only takes about ten minutes to locate and fix, or a involved fix, requiring hours and hours to reclaim refrigerant, remove coil/pan and replace, then pull a vac on the system and recharge. Please let us know where water is coming from, and if you notice any ice on the lines coming into coil. We will try our best to help you with the easy fixes, or let you know if its time to call in an onsite pro. Good luck

If you had to put freon in last summer, odds are it is low again and your unit is frezing up causing your water problem

True it could be low on refrigerant or the drain is restricted. Locate the drain on the out side of the home and suck it out with a shop vac. Give it a try and see if it helps the water problem.