Is the price on the D cell correct? Amazon and Costco both have D cells for around $1 each.
Do you have links for the deals you’re looking at?
Amazon, 12@ $14.50
Edit: I guess Amazon has the “Pro cell” version, which I guess isn’t technically the same…
Duracell Procell D 12 Pack PC1300 https://www.amazon.com/dp/B00GNLVH70/ref=cm_sw_r_awd_fEtiwbS5EZMBQ
Costco, 2x14 for $14.89 each
http://m.costco.com/Duracell-D-Alkaline-Batteries-14,-Unit-2%2B-Pack-Pricing.product.100085369.html