So let me get this straight.  You honestly believe that an operation which is aggressively trying to rent land is going to make an offer on something, and then turn around and two or three weeks later, refuse to rent it for the price they offered?  Yeah, right!   This isn't like buying a tractor where if you don't take it today, they might sell it before tomorrow and not have it anymore.  If you don't accept the offered rent today, it's 99.99% certain that they will pay the same thing tomorrow or next week.  

And still, we are back to the point that it was the OWNER who decided whether to wait for other bids, go looking for other bids, or whatever.  Anyone, including you, has th right to offer anyone anything you want at any time.  The guy making the offer has no control over what the recipient does.