Weird. Whenever I donate locally, I get what they call a "blood coupon". I can choose to leave this in my account, give it to a certain person, or put it in a pool for those with financial problems.
This coupon covers that cost of blood used by whoever redeems the coupon.
Even if you choose to give your coupon away to others, the price of the blood will be covered if you need blood within a two year period of donation.
On a related note: I called the coordinator I normally work with at the blood center after reading a post last week about CF patients not being able to donate. She took basic info and looked it up and said there was no problem with me donating with the drugs I am currently taking. She said the only thing that I need to make sure and do is provide an updated list of medicines I'm taking each time I donate.
I would want to ask a lot more questions about this fee for donating.