There is a certain hierarchy within the cards, with the plain "commons" and "uncommons" being the cheapest, followed by the "rares", followed by the various "reverse" (or "alternate", since they're no longer actually "reverse") holos, followed by "regular holos", and on up to the "ex" ultra-rare holos. The card dealers out there buy lots of cases of boxes of packs of cards, and sort through them, primarily looking for the high-value holographic cards ... this process leaves them with tons of common and uncommon cards (and non-holo rares) on their hands.
Over the last four or five set releases I have waited to find these cards for sale on eBay, as I can, "in one fell swoop", get all the non-holo common, uncommon, and rare cards for a particular set, giving Daughter #1 a pretty good collection of that set, which then only needs to have the various holos added (with the reverse holos often being snagged at a penny a piece!).
I had so far been stymied in these efforts, and even today lost on an auction for a "complete non-holo set" of the new Deoxys Pokemon cards. However, the same seller had a set of the uncommon and common cards up and a set of the rare cards up in separate auctions ... and I ended up winning these (actually, I only outright won the common/uncommon set, but the winning bidder pulled out and I got the other on a "second chance" offer).
What is really great is that I was able to get all 80 non-holo Deoxys cards (including shipping on both auctions) for less than what two packs (of nine cards each) would have set me back at Walgreens! I actually had the full set offered to me as well on a "second chance", but I got the two others for a couple of bucks less, so I declined that offer.
I can't wait to tell #1 in the morning that I scored the complete non-holo Deoxys set!