Why pay interest on equipment if you have the cash?  I would rather pay cash for the equipment and utilize a line of credit for periodic cash flow needs.  You would most likely wind up paying less interest.  Why enrich the bankers any more than you have to?  

Sell the crops when you get the best price.  Trying to guess what the economy is going to do is an exercise in futility.  Why make a difficult job (marketing) any more difficult than it has to be? 

Personally, for the last several years I have only purchased equipment out of operating profits (and you can definitely tell it by looking at my equipment).  The only thing financed at fixed rates was land.  A line of credit has been utilized whenever cropping expenditures exceeded crop marketing income.  Not saying this is the best way to do things, just what has worked for me.  

We each must determine what works for us and what we are comfortable with.  That is one thing I like about this forum.  Get a lot of new ideas and different perspectives on things.  Whether we agree with others or not at least it gives us something to think about.  Life would be boring if we all thought alike.