Rcers,
You left out an important piece of information here.
How Often do you need to do this???
There is an cheap way that one requires some anchor points.
you need at least one, but two is better ratchet cable hoist(s) (15$us at hazard fright) and a tongue jack wheel if you don't have one. Find the anchor points or make some with dog tie outs, then hook onto the trailer in two places and move it. If it is a tandem and you have to pivot around one tire, the other on that side will have to go sideways. Pick that tire up enough to put: Old glossy magazines, wet plastic film or a tire dolly : under it. You may also want a wheel chock or two. I used to do this several times a year with a 26' 4700# sloop on 1500# trailer (6200 on a scale and up about 3') just to get it where the ordinance officer would leave me alone.
There is also now a thing that I have seen called Easi-move that uses remote controlled electric motors to move the trailer. I sure it isn't cheap, but it could be your best answer.
Good Luck
Matt