Yikes the Novolin R is $150 now. They have Novolog vials and pens less expensive but they're sure not $25 anymore. Boooooooo. Probably require a script now too. Maybe it's hiding and I just can't find it. You could always call the Walmart pharmacy and ask if the $24.88 insulin is still available.
For your roommate, there's a few patient assistance programs out there if they didn't expand Medicaid in your state.
I take both long acting and short acting insulin. Some manufacturers are offering all the insulin you need for the month for a flat rate. Sanofi actually has a savings card for $35 a month if you don't have insurance.
https://www.lantus.com/sign-up-for-savings
Have them check out patient assistance or savings programs for the manufacturer of their insulins. Or they could switch to one that offers the cheapest option. I'll have to switch both mine at the end of the month when I lose Medicaid coverage. Better to switch and pay $25 instead of $100.
ETA: It's such a pain in the ass to have to jump through hoops to get affordable meds sometimes. And the programs aren't advertised as much as the savings cards which are usually only good for people with commercial insurance. You have to go sleuthing around for the info and sometimes there's a form that your doctor has to fill out and fax in. Kind of hard to get all that done if you're depressed as shit and barely have the energy and motivation to get out of bed.