I so wish I could have found a set that low in cost 30 years ago...
I got my set through Irelands/Magic Inc. in Chicago when I was about 15 but the two most popular performances of the bubbles would be Doug Henning in one of his earlier specials and Vito Lupo sometime in the late 70's/early 80's... he did an awesome mime clown act in which the bubbles played a featured role.
I would check to see if the Fakini Company is making these in that they make some of the best manipulation balls on the market. They might cost a bit more than some, but they really can't be beat when it comes to handling.
Another suggestion I would make is to learn how to work with real bubbles, what some call "Super Bubbles" (because they don't burst easily and have a longer life span once created).
These Super Bubbles will allow you to do a kind of juggling bit of business with them, including some very cool IT controls. All of which lends itself well to a short contact juggling style sequence as well as a floating ball type act using a large clear "bubble"
Wish I could be of greater assistance but hopefully this helps you on the creative and research side of things.
