Looking for cheap Dual Enrollment credit for homeschooled sister

[muu9]

My sister is about to start homeschooling to hopefully get (transferrable) college credits easier. I was looking for cheap DE courses. We're in Massachusetts, where all the community colleges are pretty expensive. I'm hesitant to go the Pierpont route as it seems unlikely that a selective institution would accept the Sophia credits within the BoG AAS.

So far I've found WTAMU's dual enrollment program, which is just $150/course. This would be all we needed if it wasn't for the fact that enrollment in more than 2 courses per semester would require approval of the provost. Luna cc is listed on the wiki as being $44/credit, but I can't find that on their website. I'm also unclear how SARA makes enrolling difficult.

Does anyone know of dual enrollment programs which, like WTAMU's, are discounted for high school students?

Also, does Accuplacer testing follow a student or would she have to redo it for each college?