I'm going to go out on a limb here and say this sounds like a bunch of lost souls trying to find who knows what....
If you want old wood screws like for a replacement for 1890's or the like you will have a hard time finding them and if you do then they will be used or a stash someone saved for a very long time. I've had to do some work on older things and I have a small collection of these. I've also spent time looking for some other sizes and got quotes of $5 a screw and that was some years ago. So for most people this is not what you want.
If you are staying current with screw technology you will know about Spax screws. They are expensive and are used by trades people who want a screw that doesn't require drilling holes or counter sinking. They are expensive and I have already mentioned them but I expect people didn't take time to look them up. That being the case I have a single link that will get you started looking at these. Love'm or hate'm they are what they are.
http://www.highlandwoodworking.com/inde ... rodID=4769
I have a small quantity of these on hand and have been impressed by them but due to high prices I don't often use them anymore.
Now if you don't mind not having slotted heads and can live with drilling I might mention these:
http://www.woodcraft.com/family.aspx?Fa ... 35&pcs=fam
You can click on more details for some other options.
Now for you that want things like un-plated etc etc. This is a site just for you to play with. They do custom work at your expense but you might contact them to see who they might sell to and pursue that route.
http://www.narragansettscrew.com/
The ace hardware still has a good selection and you can get boxes of 100 so for those not so dedicated to an ideal might want to check online to see what they might offer or stop by your local store.
Now for those of you who just have to have the old style screws from the 1890's the bidding will start at $25 a screw....
Ed