I have the Grace Pinnacle. It will support a machine with an eighteen inch frame, if I ever go to a bigger quilting machine. $400 is a great deal, as I found a new one (Grace Pro) for $1200 +, so the next question is how serious are you about quilting.
When I bought the BabyLock Quilt Pro machine and the Pinnacle frame, I thought I could live with that set up, though I knew of slightly better systems ... working in six to eight inch depths got old really quickly.
Still ... for a beginning system ... four hundred dollars isn't that bad an investment.
Last week, my daughter had me quilt her grandmother's flower garden without doing all the rails - - as in, she basted the three layers of top, batting, and backing together, we loaded it on to the take up rail and the top most rail which usually holds the backing ... it worked fairly well. Much easier that pinning the backing, loading the batting, pinning the top. Keep us appraised of how it all works out for you.