Seeding Buckwheat as Cover Crop

I'm looking to buy buckwheat to plant as a cover crop in my garden and see that you carry it but I am unsure of the quantity that I will need. My garden is about 30 ft by 100 ft. I will need enough for two plantings as I have been told that it only takes six weeks to grow to the point where it can be plowed under and there will still be a lot of summer left. Could you please advise me on amount, cost and delivery time? I don't have a credit card so will need to know payment options to get the product asap.

The recommended seeding rate is 55-85 kilograms per hectare. Your area is 3000 square feet, while a hectare is 2.5 acres or about 100,000 square feet. Therefore you need about 4 kilograms to do the two sowings.
You may pay by cheque or money order. At 2001 prices, 4 kg is $80 and 10 kg is $120 (in Canadian funds). These prices include shipping, but not taxes, for which you need to include an extra 15% for PST and GST.