Meritline offers this Mini Wireless Bluetooth v2.0 Class 1 USB 2.0 Adapter for $1.99. Coupon code "MLCKA18HNL1" drops it to 95 cents. With free shipping, that's tied with our mention from last October and the lowest total price we could find for a comparable adapter today by about a buck. This features a maximum operational range of 60 feet.
Expect this item to take two to three weeks to arrive.