You can find them on ebay instead of Amazon.Oh! I've been meaning to ask! Where does one get cheap/free pots for seed starting (and not Amazon)?
Getting crafty is another option. Egg cartons, solo cups, toilet paper tubes, newspaper origami cups... all of these are options.
While I do but on Amazon, I also shop other sites and stores. I tend to prefer reusable starter trays to save money in the long run for less delicate plants. For more delicate plants I use starter trays made from recycled paper because I can plant the entire starter cell into the beds later.