Math B.S. to Engineering

[dfrecore]

Since it's a 2nd bachelor's degree, you probably just need courses in the major.  You won't need any alt-credit at all.

So I would look for an online degree for the best price per credit, because alt-credit acceptance is moot.

I think you understand my situation perfectly... and perhaps I should update my post to better clarify. 

I should be about 30 credits from the second bachelor's (I have some engineering classes to transfer too, not just math), but I need to find a school that will both accept 90+ transfer credits and also offers the remaining classes online (and preferably self-paced and reasonably priced... but I know I'm dreaming).

You actually don't need to find a school that accepts 90+ transfer credits; you need to find a school that allows transfer into the major.  The 90+ transfer credits is moot (just like the alt-credit).  This is a second bachelor's degree, and you're conflating a first degree policy with a second degree policy - they are not the same.

I would just start to search for online engineering degrees (whichever type of engineering you're looking for), then look at the number of credits left x price per credit to get a price for each school.  Then see if any will allow transfer in the major (some won't).