See the upper right corner of your posts? The blank space where you could add a little bit about yourself, your name, location, etc.?
I'd be more likely to take you offer seriously if I knew a bit more about you and how you are growing out these seeds.
Others may feel the same.
What is your climate? With more than 300 types of plants how do you segregate varieties? How large are your growing plots? How large are your greenhouses? Under what conditions are the seeds being stored? How old is your seed? Are you offering seeds you harvested yourself? or will you be sending stuff you bought from yard sales and from eBay/Amazon/Croatia, etc.?
Stuff like that would help us to know you better.
I did take the time to check out your website....