You might compare price at
http://www.poolplaza.com/ just to make sure the price you are looking at is in line. Since I replaced mine with pretty much the same filter, changing it was a piece of cake. The hardest part for me was digging and hauling off what was 600 lbs dry sand, more when it was wet. It honestly wasn't as bad as it sounds though
I figured my old filter got its money's worth, I can't imagine changing the parts in the filter I got rid of due to the access hole being so small. The newer ones have a MUCH larger hole in top, a better sand drain, etc. So for me it was worth the $800 expense.