Mqidwai via eBay offers this WaterFall Soap Saver, model no. 82-4114, for $6.51 with free shipping. Opt for in-store pickup to dodge to the $5.97 shipping charge. That's the lowest total price we could find by $4, excluding the mentions below. This soap dish drains water from the bar to purportedly avoid wasting it or having it go mushy.
Close prices: Walmart offers it for $7 with free store pickup. Amazon charges the same with free shipping for Prime members.