You have observations, I have answers. 🙂 I have donated plasma on & off for idk 12 years or so. I know precisely how the system works.
Donating 2 non-consecutive days is for your own health; your body needs to recover & replenish what has been lost. This isn't dystopian. They pull up to 880 mL of liquid out of your body, most of that is water btw, but FFS your body needs time to produce more plasma. To heal your skin puncture. They don't care if you're upset, they won't allow you to ruin your health under their care.
I do not know your specific plasma outfit, be it Talecris/Grifols, CSL, or other, but you ought not get charged if you use your card at an ATM in the accepted network of ATMs. You get unlimited free balance checks & 2 free withdrawals of cash money per donation. With most ATMs, you can withdraw $300 max in one go. So here's what you do....fuck all the small stuff because it's a waste of time, multiple trips & whatnot. Let your balance build up to over $300. Withdraw $300 in one go. You will never be charged a withdrawal fee.
Additionally, if you have multiple plasma donation clinics in the same area, you can play them against each other for new donor fees. Get $700 in one month donating at one. When the new donor fees dry up, bounce & go to the other clinic & suck up their new donor fees. Stay true to the second one & stay away from the first for 5 more months, guess what, you're a new donor again at the first clinic. Rinse & repeat.
I feel you on the nickel & diming sentiment, it's true -- it can only, maybe, sometimes be overcome with forethought & investment. See the boots theory. It's expensive to be poor, some of my poorer friends pay so much more than I do for certain things. The same things. Usually they're buying out of convenience & not buying on sales, or in bulk. It breaks my heart, really.
Also pro tip, just be really positive & calm when you go in for donations. The staff is dealing with angry people, crazy people, dumb people, very smelly people, drug addicts, the desperate, the destitute...etc etc etc. Every single day. And if you give them any attitude (even if you've got a good reason!) & they decide to make it a problem for you, they can defer or ban your ass. It's solely their discretion. Think twice. Be nice.