I'm just an operator so I'm not sure about the specifics, but here's what I've learned and or heard from the grapevine....:drinkup
It costs a lot to move equipment, because of weight, height, length, width. It all factors in. and once even one of those items is exceeded by a certain amount you need to apply for permits, which cost money. I'd imagine there are general permits that can cover most loads for a specific trailer, and then "special" permits, for the real big stuff. Cross state lines, it gets even more expensive cause of different weight laws, etc. On the big stuff, you need to plan out routes with proper clearance and weight capacities, etc... usually a longer distance, more fuel.
For example, our 345's are an oversized load, but in PA we can get away with just an escort (typically the rolloff with the c/wt and bucket(s)), but when they are moved in DE, they are considered a "super load" which requires special permits ($$) a police escort ($$). Another example is when we had our 385 lme, it would cost something like $20K to move, not including dozers, or the 740's. That's $40,000 dollars per job, for one machine.
So if you don't have another job right away for it to go to, and the room to "store it" on that job, then it's more cost effective to leave it there and just move it once, than to move it to the yard then from the yard to the next job. Hope that helps and that I'm somewhat accurate, if not I'm sure someone here will know the right answers
ointhead:usa:notworthy