These days, that's not everything. Even at thrift stores, you have to be careful. The store where we volunteered, bless its heart, had a thing (just for example) about pricing shoes according to their bought-new value; you would not score a pair of expensive running shoes there for fifty cents. Sometimes I saw stuff in the housewares section (and not just in that store) that cost more than its dollar-store counterpart. Yes, if you buy it from the thrift store you are giving an item a second life, and helping out the charity that runs the store, but still there isn't much sense in paying more for a used whatsit than you'd pay for an identical new one.
Actually, that's a good rule of thumb for whether or not you can expect to get a great price on something at the thrift store. If it's something that every thrift store in town is constantly overrun with, never runs short on...they will probably price it/them cheap to keep them moving. Examples: children's board games, and certain types of toys and children's books--there always seem to be more where those came from. At our store, the toys were often bagged up in bunches, but even if you had to buy the whole bag, it was still a good bargain. If it seems like every other person bought a whatsit, and it was the sort of whatsit that not everybody would end up really using, or at least using more than a few times, your chances of finding one used are probably pretty good. Small or smallish kitchen appliances, especially fancy ones or the things people get as gifts, fall into this category. If you like to experiment with slow cookers, bread makers, or those seen-on-TV grill machines, check the thrift store first.
And how do I say this one nicely...if you have some kind of interest or hobby that goes beyond the knowledge level of most thrift store staff and volunteers...you might find a bargain in your tiny special area of expertise, and that includes homeschool curriculum. Because nobody knows everything about everything, and even the very knowledgeable "book boss" at the store where we volunteered had areas where he knew a lot, and other places where he knew as little as anyone else (such as "ladies' crafts"). If you love hot rod books, or opera scores, or weaving, you might find the treasures of a lifetime in the "let's get rid of this cheap" section. You might find a hardcover Apologia textbook in with kids' books, or dumped in with dog-eared college textbooks--how's a volunteer supposed to know the difference?
If a store doesn't get much of whatever-it-is, they're also not as likely to know what to do with it or where to put it, or, sometimes, even what it is. Plus, customers (as in any retail establishment) sometimes come along and mix things up, pick something up in one section and put it down in another. The first day I ever helped in books, I found a copy of Heidi shelved with the horror and fantasy books. So that's my final piece of advice: if you're in a thrift store that has things all nicely labelled, and you have any extra time...look in the wrong sections. It might pay off.
Oh...the photos? That's a game I got for a birthday present when I was about six...the object was to not "get skunked." I've never seen another copy of Skunk, at least in real life, although I still have the dice with little skunks instead of ones. Looks like you can buy sets used online, though.