Try valueseeds for inexpensive seeds. It is the clearance outlet for T&M. Shipping is a flat fee of $1.99 and all seeds are .99 cents or less. The seeds are sent without the outside packet so you have to do some work in getting the instructions for planting and growing but it is all found on the website. They list new seeds a couple of times a year so you have to keep an eye out for the new listings. Some sought after items sell out almost overnight. Shipping is quick and well done.
spiderwoman

Fedcoseeds!
They don't sell seeds for 25 cents a pack, but they do have an exhaustive selection of heirloom and open-pollinated seed, they don't do business with Monsanto or carry genetically engineered seeds (they do carry hybrids; hybrids and genetically engineered life forms are not the same thing, for those who may not know).

Plus, they have a lot of Organically Grown seeds for those who want to know that what they grow is 100% organic.

They do their own trials and tell the results openly.

I've made a list (& no, I don't make any profit off of them) of seed & plant companies on my website. Not sure which ones will be cheap, but just click on the ones that interest you.

Here is a link that might be useful: seed sources