I have a 2000's proof set and I took them out of the plastic casing and put them into 2x2 cardboard coin holders... Will that increase or decrease the value? I only touched the sides and didn't let them touch anything else
Depends on the ultimate purchaser. The act of taking them out if you were careful shouldn't affect it if you were careful. Individual coins are wanted for people who only collect on denomination, with the Kennedy usually the most valuable by far.
I mean you could look up and compare prices for your individual coins vs the proof set. You could compare on ebay too.
I have a Kennedy! I'm happy I took them out individually! They are worth more than the set... about $10-15 more
But remember that is like a cars parts being worth more than the car. The value only comes after you have sold all the parts. Including time and effort, packing and shipping. There are people who break open sets to remove the one coin that goes with their collecting interest and then sell/trade the rest of the coins to recoup some of the costs of the set.