I was in a hurry when I posted last time, and I want to elaborate some. If you're just starting out, don't go hog-wild like I did buying blanks on eBay and other places. You'll wind up with a bunch of so-so stuff, and a handful of really nice blanks. Instead, buy stuff that you know you'll really like. Let me give you an example. One of my favorite woods, if not my out-and-out favorite wood, is Cocobolo. I did a lot of eBay shopping when I first started turning (only a little over a year ago), and I know you can get Cocobolo blanks on eBay for $0.50 a piece, and some times less. The problem is, they're going to be straight grain, average blanks. Sure, the make pretty pens, but they'll look like everybody else's pens. After about 9 months of turning these blanks, I realized that regardless of whether I'm making the pen for a gift or to sell, some eye-popping grain in a blank is worth the extra $1 or $2 to make that pen extra special, even when money is a little (or a lot) tight.
Basically, I'd rather spend $2-3 per blank and have something that really catches your attention, than $0.50 and get something average. It's these attention-catching blanks that you'll frequently find in the individual and group classifieds here. And, best of all, the people who list here tend to be wood turners, if not pen turners, so they understand what we're looking for in pen blanks. Their "rejects" or "seconds" are frequently better than a lot of the stuff you'll find on eBay.
If, despite my sage advice, you still want to purchase really cheap blanks, let me know, or contact one of the guys listed above. I have about 5-10 lbs of blanks that are in a bag in my dining room. They're there because I won't use them and I want to find a good home for them. I'm sure we can work out some kind of trade. Similarly, if you look in the classifieds here, you'll see that Rob and Chitswood recently "purged" some of their "seconds" (which had some beautiful stuff in them!), and I'm sure if you contact them, Dario, or any of the others, you can get some of their "seconds" for a very reasonable price.