ebay. the cheapest and not always bad. check seller ratings first.

I visited Foxfire Gardens this past weekend and they had a lot of minis. They do mail order.

Here is a link that might be useful: Foxfire Gardens

Trade,the best way to add to your collection.Brenda

THere are many reliable nurseries to order from who do carry minis.

Hallson's
Jim's Hostas
Miniature Plant Kingdom
Plants Delight
Direct Source Hostas

If I can't find them locally, from 8 Hosta vendors (and usually not), then I purchase Minis from Naylor Creek. They have a large selection.
Check out the Hosta Library Auction, also. There is often a number of Minis listed.

Good vendors are: Northern Grown Perennials (WI), House of Hosta (WI) and Flying Frog Farm (IA). I have been pleased with all of these. My local farmer's market has several vendors that have lots of minis. That may be another option for you.
I have several dozen varieties and really enjoy them...have fun with your new collection!
Marlene

Plant Delights definitely.