As one of its daily deals, Amazon offers the RVBX: Ten Years of Red Vs. Blue Box Set on DVD for $42.49 with free shipping. That's the lowest total price we could find by $28. It features 10 seasons on 14 discs, with extra mini-series, behind the scenes footage, and interviews.
Of note, the box set is also available on Blu-ray for $53.99 with free shipping. That's another price low, this time by $53. Both deals end today.