Is there a limit to what I can make?
Not really, but you'll find you're limited by time!
In most cases adults will make two or three 'canes' (patterns) and from those, they'll make a number of different items including pendants, earrings, key rings, cufflinks etc.
I ask that any bits of unused canes are left behind so that the clay can be re-used. If you've made a pattern you really love, you can buy it at cost price (I bring scales so we know how much clay each 'cane' contains). It works out at around £3 for 100g.
Bear in mind that larger projects won't cure properly in the oven in the 30 minute curing I suggest in the instructions. Under-cured items are fragile and will snap and crumble, which is a waste of clay and effort as well as being very disappointing for the creator!