LumsingDirect via Amazon offers the Lumsing Mini DisplayPort to DVI Converter for $8.99. Coupon code "M2A25F5Y" drops it to $3.60. With free shipping, that's a slight drop from our February mention and $2 under the lowest price we could find for a similar adapter elsewhere that's shipped from the U.S. It's compatible with Thunderbolt 2 and supports video resolutions up to 1920x1200.
Don't need it soon? Hong Top via eBay offers a similar one for $2.89 with free shipping. It ships from China and may take up to seven weeks to arrive.