That's what I had suggested to DD's teacher before someone mentioned MobyMax to me.
When I grilled the online rep I wasn't entirely happy with some of her answers to my questions, but it does have a pretty good reputation + a cost that the school won't balk at (and it should be their expense since she'll use it at school).
One of the advantages of MobyMax seems to be that it's more adaptive, and will let DD start where she is ready to start, whereas EPGY (according to the rep I grilled last month) will make her start at the beginning of a curriculum year and work through the entire thing. So in EPGY, she'll probably have to re-do half a year of 5th grade math to get to where she "should" be.
