Amazon offers Prime members the Estes Proto X Nano Remote Control Quadcopter in Black, Purple, or Red, model no. ESTE48LL, for $29.99 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, it adds $6.08. RC Superstore via eBay offers it for the same just in Black.) That's the lowest total price we could find by $5. It measures 2.6" in length and features a 2.4GHz transmitter, LiPo battery, remote control, and LED lights.
None of those colors suit? Amazon also offers it in Green or Yellow for $30.25 with free shipping for Prime members.