communal purchasenoun.
The purchase of a large quantity of a single item by aggregating individual buyers.
Example Citation:
"Here's how the new world of communal purchasing works: You place an order for a Palm V, say, and give Accompany 72 hours to assemble a group of buyers. Accompany will bundle you with other Palm V seekers25, 100, 500 at a timeand negotiate a purchase in bulk, so you can share in the kinds of stepped discounts usually reserved for larger corporate buyers."
Chip Bayers, "Why Buy Retail?," Wired