I do mail order from Upton Teas (https://uptontea.com). They have most teas available in sample packs of between 10 to 20 grams. They also have sampler packs of four tins, each with about 35g of a different tea. Personally I’d hold out until their “Introduction to Fine Tea” sampler is in stock again, but they have other sampler packs available.

They’re on the expensive end, but I’ve never found a store front with loose leaf teas having tea as fresh as Upton’s. Many of their teas are single estate teas, but they also have blends, flavored teas, decaf teas, and herbal teas (tisanes).

Since they’re in Massachusetts (Hopkinton, I think, in spite of their name), the cheapest shipping is usually next day by mail.