Yes, Tophatter does offer reserve pricing.
Although most products do not have the option to set a reserve price, some products on Tophatter may be eligible for a reserve price feature. Reserve pricing, would require that bidding surpass a specified reserve price in order for the product to be sold. Eligibility varies on several factors, if a lot qualifies for reserve pricing there will be a Reserve Price field next to the product on the Seller Products page.
Keep in mind that if there is no Reserve Price field the product may sell for less than the cost basis.