I like to look thru mint sets at coin shops and buy a single coin from the set. I try to find the MS67 and MS68 PQ coins from mint sets. I always leave the coin in the original mint cello. I then put them into the 20 coin 2x2 pages. Do you leave them in the cello or do you put them in 2x2's or something else?
I wasn't saying it had added value, I usually just leave them in there for added protection. Plus if they have some toning, I always leave them in the cello, in case I decide to send them in to get graded. I have never had a coin BB when I send them in the mint cello.
That's my feeling too. If it's for myself I would just as soon take it out. If I'm keeping it for potential sale, I've found that buyers are more confident with a coin in the Mylar. They know that it's very unlikely to grade out as AU if it's still in Mint plastic.