hair by electrolysis, was found to be an offer as the plaintiff paid for the treatment on the basis of the offer. The display of goods in store is typically an invitation. The quotation of the lowest price is also considered an invitation. However, in some circumstances a quotation will be an offer. In Canadian Dyers Association Ltd. v. Burton, [1920] 47 OLR 259 (HC), a quotation followed by the statement "if it were anyone else I would ask for more" was considered an offer. A call for tenders is usually considered an invitation. In R. v. Ron Engineering & Construction Ltd., [1981] 1 S.C.R. 111, however, the Supreme Court found that a call was an offer where there the call was sufficiently "contract-like". Later, in M.J.B. Enterprises Ltd. v Defence Construction (1951) Ltd., the Court again found a call to be an offer which was accepted with the tender submission (known as Contract A). In Tercon Contractors Ltd. v British Columbia (Transportation and Highways), the trial judge summarised the factors to be considered in deciding whether a matter constitutes a call for tenders or a non-binding request for proposals: Consideration In common law jurisdictions, consideration is required for simple contracts but not for special contracts (contracts by deed). This means that each party to a contract is required to exchange something of value and that a gratuitous contract is not valid in Canada's common law provinces and territories. Where one party retains discretion over the performance of an obligation under a contract, that obligation constitutes a "mere option" and therefore cannot serve as valid consideration. While the purpose of the doctrine was ostensibly to protect parties seeking to void oppressive contracts, this goal is currently accomplished through the use of legal principles enabling the recission or annulment of contracts on the grounds of unconscionability, through purposive interpretation of contracts by the courts, and through equitable remedies. In practice, the doctrine of consideration has resulted in a phenomenon similar to that of Ḥiyal in Islamic contracts, whereby parties to a contract use technicalities to satisfy requirements while in fact circumventing them in practice. Typically, this is in the form of "peppercorn" consideration, i.e. consideration that is negligible but still satisfies the requirements of law, although Canadian courts may evaluate consideration for "sufficiency". The requirement for consideration is the most significant difference between contract law in Québec and the common law