Diane - I saw your items on Facebook and they were gorgeous! You do a very good job.
On the glass pebbles, I get mine from the dollar stores but I did see some on line too, probably ebay. Not sure if they are cost effective to buy and alter/sell but they are there.
I know you have answered this before, but how big are these that you use that you sell for $3 or more (the pebble magnets that is). I did do some and I sold a lot, but mine were 3 for $3 (although I think I could have gone up on them). But they were so cheap to make that I was making money no matter what I sold them for (the glass was $1 and it had at least 20 in there!). The biggest of mine are probably an inch or so.