It's no revelation to state that our health care system in the US has many problems. One of them is the cost of prescription and disparate pricing.
If you have private insurance or Medicare D, the cost of a prescription depends on the Tier level that the provider puts the medication in. If in a higher Tier, in some cases it may actually cost you more for the Rx than the everyday cash price, particularly with Medicare D which unlike the Veterans Administration, is prohibited from negotiating with pharma companies for lower prices.
As an example, I use a common generic ointment. In Tier 1, a 30 gram tube of ointment cost me $1. Last year it was dropped from the insurance company's formulary and my cost became $71. Someone suggested that I check the item at GoodRx, a "pharmacy discount card" provider. Lo and behold, the cash price with the coupon printed from their web site was only $30.
I don't know what GoodRx gets out of this. Similarly, I don't know what your "pharmacy discount cards" from the "Massachusetts Prescription Assistance Program" offer or what they get out of it. And when push comes to shove, does it really matter? Obtaining your medicines for less is the only issue.
Contact the appropriate regulatory agency in Massachusetts to verify that the organization in question is legit. Then start comparison shopping.