I would recommend checking out the Wiki as it has a list and the links to all the free courses. Without knowing what your 48 credits are in its hard to direct you to specific sources. Typically you would start with the free courses -
NFA
Ethics
TEEX
The next cheapest would probably be Aleks. It is $20 a month and you can take all their math courses, unproctored, as many as you can fit in.
The next cheapest would probably be Saylor as the course material is free and the exam is only $25.
Then there are your subscriptions like shmoop where you pay a flat amount per month and can test through as many courses as you want.
Subscriptions from Study.com and Straighterline are a flat monthly amount (except with SL you also pay a per course fee) and that includes your books/exams. The more courses you can complete in a month the cheaper it usually is.
Beyond that, there are many other ways to obtain credits (CLEP, DSST, other providers like Sophia, Ed4Credit, etc). Maybe as a start, post your credits and someone on here can direct you to particular courses.
NFA
Ethics
TEEX
The next cheapest would probably be Aleks. It is $20 a month and you can take all their math courses, unproctored, as many as you can fit in.
The next cheapest would probably be Saylor as the course material is free and the exam is only $25.
Then there are your subscriptions like shmoop where you pay a flat amount per month and can test through as many courses as you want.
Subscriptions from Study.com and Straighterline are a flat monthly amount (except with SL you also pay a per course fee) and that includes your books/exams. The more courses you can complete in a month the cheaper it usually is.
Beyond that, there are many other ways to obtain credits (CLEP, DSST, other providers like Sophia, Ed4Credit, etc). Maybe as a start, post your credits and someone on here can direct you to particular courses.
MTS Nations University - September 2018
BA.LS.SS Thomas Edison State University -September 2017
BA.LS.SS Thomas Edison State University -September 2017