velve'u lujvo

x1 is the sales price of x2 to x3 from/at vendor x4.

x1 is also the revenue taken in by x4 for x2 from x3 under the condition of a sale (as opposed to ex-nihilo mining); one person's cost is the other person's revenue.

In notes:

x1 [seller] sells/vends x2 [goods/service/commodity] to buyer x3 for amount/cost/expense x4.