First, however, we consider the other contexts in which this court has previously discussed whether evidence of a paid bill, standing alone, reflects the reasonable costs of the product or service. In Farris v. McCracken , 253 Or. 273, 453 P.2d 932 (1969), a case dealing with enforcement of a mechanic's lien filed after nonpayment of a disputed contractor's bill, this court considered whether evidence of the contractor's paid bill was sufficient to establish that the costs paid by the contractor were not excessive. In that case, the plaintiff—the lien claimant—presented evidence consisting almost entirely of his own alleged costs without providing any explanation of the basis of the charged amount.

To know whether a charge is reasonable, a factfinder must have some sense of the relevant market. See Campbell , 296 Or. App. at 30-32, 438 P.3d 448 (concluding that charges for medical services are reasonable if they are at or below market rate); see also Farris v. McCracken , 253 Or. 273, 453 P.2d 932 (1969) (explaining that bills alone were not sufficient to establish "open market selling price" of materials and services supplied by contractors). The Supreme Court made this point in Farris in explaining why the plaintiffs’ evidence was not sufficient to prove the reasonable value of the materials and services for which they were seeking payment:

Similarly, CCE's evidence that the amount charged for the materials was reasonable will not support an inference that the amount of materials used was reasonable. See Cloud v. Riddell, supra; Farris v. McCracken, 253 Or. 273, 453 P.2d 932 (1969). Therefore, defendants' motion for a directed verdict was properly granted.

To support a claim for the reasonable value of labor and materials, one must prove that the labor and materials were actually expended for the benefit of the defendant, that the amounts of labor and materials used were reasonable and that the charge for those amounts is reasonable. Farris v. McCracken, 253 Or. 273, 453 P.2d 932 (1969); Timber Structures v. C.W.S.G. Wks., [ 191 Ore. 231, 229 P.2d 623 (1951)] 596 P.2d at 583.

Plaintiff presented evidence on the fair market value of the completed house, but that value is different from the value of the labor and materials furnished. He offered in evidence all the invoices received from his subcontractors and evidence of what he spent for labor, but that evidence did not show that the labor claimed or the wages paid were reasonable or that materials were purchased at a reasonable price. Credit Service Co. v. Country Realty Co., 46 Or. App. 867, 870, 612 P.2d 773 (1980) ("[T]he amount charged for materials does not, without explanation, establish their reasonable value."); see Farris v. McCracken, 253 Or. 273, 453 P.2d 932 (1969). Something more is needed.

In Midwest Fabrication v. Woodex, Inc., 40 Or. App. 675, 680, 596 P.2d 581, rev den (1979), we enunciated the following tripartite test for supporting a claim for the reasonable value of labor and materials: "* * * [O]ne must prove that the labor and materials were actually expended for the benefit of the defendant, that the amounts of labor and materials used were reasonable and that the charge for those amounts is reasonable. Farris v. McCracken, 253 Or. 273, 453 P.2d 932 (1969); Timber Structures v. C.W.S.G. Wks., supra [ 191 Or. 231, 229 P.2d 623 (1951)]." Even assuming in the present case that the materials were actually provided for the benefit of the defendant and that the amounts of the materials used were reasonable, there is no evidence in the record before us that the amounts charged for the materials represented their reasonable value.

Hall v. Gordon, 284 Or. 49, 584 P.2d 1374 (1978). To support a claim for the reasonable value of labor and materials, one must prove that the labor and materials were actually expended for the benefit of the defendant, that the amounts of labor and materials used were reasonable and that the charge for those amounts is reasonable. Farris v. McCracken, 253 Or. 273, 453 P.2d 932 (1969); Timber Structures v. C.W.S.G. Wks., supra. With respect to the charge for the labor of Hayes, the testimony was as follows: