Hey Farm jazz you have asked the million dollar question in your post.  I already have a $7.00 cash price set with our local elevator only 30 miles away for harvest delivery.  Got that one done middle of last week and also set the basis for another harvest delivery contract (Sept KCBT) and am just watching the board now.  I have takin' a blood bath by locking the board this time of year with the mentality (hope) that the basis would improve.  These large conglomerate grain elevators love if you leave the basis open.  If they get enough contracts signed and you are not able to roll them it can be like being in a "Pandora Box" and no way out.  Not to many years ago did that and watched the basis go from  -.90 all the way down to -.1.60 at harvest and had to take the beating.  My $5.50 board turned into $3.90 cash price unfortunately.  Also used to do business in to large of quantity.  Now I try to do several  smaller deals and have better average in the end.  Good luck.  I am only 40 % marketed now for new crop and just watching the bubbles.  Take care.