B&H offers the Sony A-Mount to E-Mount Lens Adapter, model no. LA-EA3, for $98 with free shipping. (A handful of merchants are currently matching price, including Adorama and Focus Camera.) Outside the price-matching merchants, that's the lowest total price we could find by $82. It allows you to attach any A-mount lens to an Alpha E-mount full-frame digital camera body; it also enables auto exposure and features a tripod mount.

Also available is the Sony A-Mount to E-Mount Lens Adapter with Translucent Mirror Technology for $248 with free shipping. (As above, other merchants are price matching, including Amazon, Adorama, and Focus Camera.) That's the best deal we could find by $38. It functions like the above item, but also enables 15-point autofocus.