I've been looking on the us mint site and the only things I see are the bicentennial cent set and sets including all denominations. Is there another way to get proofs from the mint? Like say I wanted 6 cent proofs, 12 dime proofs, or whatever. Individual pricing for individual denominations I guess.
You can't order proof circulating coins (1c - 50c) individually from the Mint-- they come in sets. If you want individual proof coins, you will probably have to buy them from a dealer or another collector.
Like others, I have some individual proof coins because I purchased Mint Sets and removed the specific coins(s) I wanted. This is how I aquired my 1970 D and 1987 P & D Kennedy halves, as it was way less expensive doing it this way than buying them individually. Though I'm not interested in selling what I have, others in similar situations may be.
Many times, if you buy the new sets direct from the mint, you can sell some of the coins you do not need for your collection, and recoup some of your losses. If you need proofs from say 2006 or earlier, you can pick most sets up pretty reasonably right now.
I have noticed in some years that the number of individual denominations does not equal (there were more proof dimes made than quarters). Where do the extra's go?
It depends on the dates. In the early years, prior to 1950, Proofs were not manufactured and sold as sets but rather individual coins. And after 1950 there were some years when the annual Proof set as well as some smaller 1, 2 and 3 coin Proof sets were made and sold. That's why the numbers are sometimes different.