BuyDig offers the Tamron 75-300mm f/4-5.6 LD Lens for Canon (pictured), model no. AF276C-700, or Nikon, model no. AF276N700, with a $50 BuyDig Gift Card for $167.28 $147.28 with free shipping. Assuming you'll use the gift card, that's the lowest total price we could find for either model by at least $47.

Also available is the Tamron 18-270mm f/3.5-6.3 Di II VC PZD Lens for Canon, model no. AFB008C-700, Sony, model no. AFB008S-700, or Nikon, model no. AFB008N-700, with $75 BuyDig Gift Card for $457.98 $437.98 with free shipping. That's another price low by at least $57, assuming you'll use the gift card.

Update: Of note, coupon code "VMESAVESU20" cuts an extra $20 off, reflecting the above prices.