You might want to try and sell them in lots on Ebay - I see that being offered there a lot, and it's probably the easiest way for you. There are a lot of home sewers out there who would be interested, or vintage pattern dealers like me (I have just bought a lot of new stock myself though, so I can't keep buying at the moment - need to make some $$$ first). So it would be a shame to just throw them away. You can also check what prices such lots sold for on Ebay to get an idea. Even if you sell in larger lots, it's important that you take some good pictures to give your buyers an idea what they're getting into. And I would probably put them into lots like children's wear, crafts, women's clothes, men's - and if you really have a lot like maybe women's you could also think about putting them by decade, whatever suits you. Doing it like this will give you a better chance of selling I think, as sellers will be better able to choose what they are basically interested in. What's important though: as it seems there are so many, you will probably not have the time/resources to check if all patterns are complete, used etc. That's ok with such big lots in my view - as a buyer in this case you just take the risk of having a few not complete ones, and then maybe a few that are unused in the mix as well. However, you need to state this clearly in your listing, for example that the patterns have been used or most of them have been used and that they have not been checked if they're all complete.