Nice link LKZZ. Definitely helps out the people who grow en masse.

For the everyday gardener, seeds are definitely the least expensive part of gardening though, in my opinion. Especially if one gets in on the seed swaps here on GW. The most expensive seeds in my experience are the rare(or superhot) pepper seeds. Over 5 bucks for 10 seeds at many sites -- and if you don't know what you're doing, you can find yourself with zero plants out of those 10 seeds.

Kevin