With a laboratory experiment. we study the impact of buy-options and the corresponding buy-price on revenues and bidding behavior in (online) proxy-auctions with independent private valuations. We show that temporary buy-options may reduce revenues for two reasons: At low buy-prices. the application of the buy-option avoids revenue-enhancing bidding; at high buy-prices. https://www.shopredoners.shop/product-category/polo-cardigan/