For myself, I've decided grain bins are an excellent tool to have here on the farm.  Some farmers collect old tractors, my wife says I collect grain bins.

Some of the reasons I have to justifythe bins are:

Never a line to unload,

Open 24 hrs,

 Can market to multiple elevators,

In 200 bu corn the .10 cent minimum storage charge at the elevator is $20 per acre, if you store it for 6 months that would be $42 per acre.

In Central Mo the elevators price grain as farm stored or elevator stored, there can be 5-7 cents difference in price, another $10-$14 per acre.

These are a few of the things I use to justify them, what are your reasons for or against on farm bin storage.