Gore Inc. sells office furniture. In 2021, it sold 200 desks for $500 each. For each desk sold, Gore distributed a 50% discount coupon for purchase of an office chair within one month. Based on historical experience, Gore expects that approximately 20% of the coupons will be utilized. The chairs purchased with the coupons are priced at $150 and normally discounted 10%. What would be the stand-alone sales price used by Gore for the coupon when allocating the $500 transaction price to performance obligations