You have to look at the wording.

(a) IN GENERAL.—The Secretary shall—(1) purchase from willing sellers, at price not greater than fair market value, available agricultural land in the United States

Later on they go on to say they must make at least 20,000 land grants per year for 2021 - 2030 with each grant being no more than 160 acres. They earmark $8B per year in order to purchase land. If they do the minimum number of grants they only have the funds to offer about $2750 an acre. Outside of an area of Northern Missouri, I've not seen good farmland sell for under $5,000 an acre these days. We recently bought 100 acres for $4300 an acre and only 84 acres of that is tillable. Even then it's going to be about $800 an acre to clear a house site, put in an additional well, and regrade the front 50.

No one is going to sell their land willingly for half what they can get on the open market. And that's not prime farmland. Prime farmland in places like Iowa is going for $8,000 an acre and other places it's over $10,000 an acre.

So then we come to the In General part. The secretary should buy from willing sellers, however they are required by law to offer at least 20,000 grants per year. If they can't buy that land how do you think they'll be getting it? Well there's an interesting clause earlier in the bill about documenting "corporate farms". What is a "corporate farm"? Well the IRS considered any farm making more than $250,000 per year in revenue (that number may have changed recently but last time I had to look into it), not profit, to be a large scale farming operation. And every farmer around us, including us, had land in Trusts and operated under a LLC for liability reasons. When we got out of the business of farming ourselves we sold the LLC, and the equipment it owned, to our staff and they continue to farm our land under a lease.