I bought root stock from R. H. Shumway as 2 plant types, 2 bare
roots each. The cost at that time seemed to be just a bit over $20.00.You
should have two different varieties for pollination.
Shumway's now has the same type of offer in their catalog. "Offer includes Adams #1 and York, both hardy, vigorous varieties producing heavy clusters of fruit when planted in combination. 2 yr #1 bare-root plants. Zones 4-8, 2 plants for $24.99. Get 2 more for only 1 cent. 4 bare-root plants for $25.00.
I had really good luck on all of the roots producing greenery 2 weeks after planting. There wasn't much but in another 2 weeks there was a lot of greenery. I planted near the edge of a wet spot so the further away from the wet spot the larger the bushes grew. The first year the 2 larger produced lots of flowering heads, but the birds got the berries. The 3rd plant had several heads and berries and the smallest had only a few heads and very few berries.
After the Adams & York plants I am going to find FOUR other varieties, one plant each, and plant about 5 ft apart from the others. Hopefully in a couple of more years I'll be able to make a couple of gallons of Elderberry WINE! IF you've never tried that - you don't know what you're missing. GREAT WIND!!!
Other than Shumway's just type in "bare root elderberry" and you should get several hits for that. BUYER BEWARE!! There are some plants that I found for as little as under $10.00 and all the way up to over $100.00. Do your browser shopping BEFORE YOU BUY!
And YES, growing slips (cut on a slant) from the bushes could generate you a little income! IF I did that I would not
sell for under $10.00 each.