i just moved my 980 lb spa the other night. here are the details:
i used a 4ft metal pipe to lift under the skirts
i then placed a 8 inch 2x4 under the corner
repeated for other corner
slid 2 10 ft pvc pipe under the spa (like a roller)
pushed the spa up on the pipes
it now rolls on the pipes with little effort
i had 5 pipes in all
replace pipes in the front as pipes slid out the back
the hardest part is getting it up on the 2x4 to slid a pipe in
don't attempt unless you have a good back and a strong lifter on the metal pipe/lever