State Quarter Grades And Values

I have recently noticed a possible glitching the State Quarter collecting that I thought was strange. I don't know if it's because no one thinks they are worth much as a rule and has stopped paying attention or The grade standard of the coins is over exaggerated. I picked up a 1999 mint business set at auction and they have the MD BU sealed first 5 state all beautiful. PCGS VALUES are mind blowing for 67 67+ and 68. I bought my sets P&D for $10.and the can be bought for about the same on ebay. What is the catch if any of these coins are comparable to graded mMS68. Are they counterfeit or is this just an oversight due to being unaware of high grade value? I'm a spooked because it's 'too good to be true" or is this a potential oversight. I'm including pictures of what I'm working with. The plastic bag adds texture in the picture, the coins are high luster with minimal bag marks if any. Give me your thoughts