Actually, Paul, that's pretty good price for that many beads/rings. You'd probably spend just as much(if not more) if you go to the local hardware store for PVC pipe or brass plumbing connectors.
The most economical method I can suggest that will get you the most bang for your buck is to pick up a couple of metallic vinyl placemats, cut them into strips, and super-glue sections of the strips into ring shapes. You could probably get at least 30 rings per mat, if not more. You can adjust the sizes as well by gluing larger and smaller rings.
Additonally, a placemat like that runs about $3.00 US. You might find some at your local second hand store for even less.
Here's how I got some REALLY COOL LOOKING, CHEAP DREAD RINGS.
Contrary to the previous reply (no offense), but using PVC pipe connector pieces is VERY cheap! You can get a ton of all different sizes from any hardware store for only a few cents a piece. I got mine from a Home Depot Store ranging in cost from $0.10 - $0.37 USD for each PVC connector piece. I got a qty of about 40 or so + a few dozen other misc. ones w/ the same inner dia. but half the tube length. Compared to those on ebay, this is WAAAAY cheaper, but does take a lil' effort.
First, I loaded each of the individual PVC tube connectors, one right next to the other, onto some spare square dowel lengths I had laying around. Then, I used my Dremel w/ the #428 steel bristle brush & ran it in various cutting depths & random directions over the entire length of PVC connectors on the dowel. Of coarse, spinning the dowel once desired amount of effect was etched into the "dread rings". By doing this, it gave each bead/rings an original, unique pattern cut into it, sort of like wheather damage or scratches, easily cut/etched into every single one of them.
Once that was done, I just removed a few off one end of each dowel & evenly spaced out the remain ones so they could all be painted while positioned firmly on that very same dowel. I then used a combination of metallic & flat colored spray paint & also hand painted a few details (paint markers rule!) and finally, sealed them w/ Krylon acrylic clear coat.
Believe me, it's actually easier than it sounds, & is totally worth it for a great looking, custom-made set of rock-solid, yet cheap dread rings! I added a couple pics to show you how these looked on my dreads once they were done.
If you'd like me to snap off a few pics of what I'd tried to describe above, just let me know. I actually still have some that were "in process" & are unfinished on a dowel yet since I started making many more than I ended up needing!