Welcome Toronto!
What's your definition of cheap, Toronto? A few online places will sell unnamed rosettes for projects, landscaping, etc. but there's a price that may not be considered cheap if you want 25/50+ cultivars at the same time.
If you are willing to pay, there are people on this forum that sell their sempervivums from time to time. You may want to check the Classifieds and Group Buys forum.
I would think the cheapest way to go is to ask any fellow semp collectors if they would sell to you cheap their rosettes that they may be getting rid of from time to time for whatever reasons. They may even give them to you for free if they don't need the money.
