So my golf has about 25k mileage and I recently noticed that the AC is not cold like before. I don't really know what casued this because I have only had the car for less than a year and haven't used the AC much but since the weather got hot recently I noticed it is not cold at all. However, something I did which I am not sure if could actually cause this to happen.

I had some cologne tester strips in my car which I decided to fold and place it on the AC vents, so whenever I turned the AC on it would blow a nice cologne smell.
Could this possibly cause the problem?

I went to the dealer and they told me they would charge me $185 just to check what's wrong, if it is low on freon they will gas it up and that 185 dollars would cover it but if there is more to it they will charge it on top of 185 dollars!

Has anyone had this issue? Should I take the car to a reputable indie shop for a cheaper price?