Amazon offers Prime members the BOOMco. Twisted Spinner Blaster, model no. CJJ04, for $11.38 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it adds $6.57.) That's the lowest total price we could find by $7. It features a 70-foot firing distance, rotating barrel, and comes with 16 extra darts.
Orders placed via Prime by December 22 are guaranteed to arrive in time for Christmas. (The deadline for standard shipping is today, December 19.)