You clearly do NOT understand Buy-and-Bill.
1) An entity needs to acquire the product.
2) Said entity then bills the patient's insurance for reimbursement. Hopefully the pts insurance reimburses fully for the product + a little for profit.
3) The entity would need to be contracted w/ A LOT of insurance payers and medical groups! To be able to bill the pts insurance, otherwise the entity would NOT be able to see, let alone bill the pts insurance.
4) Step 2 & 3 are the hard parts. How many donation centers would be willing to take risk of hoping to make a small profit? How many individual doctor offices or medical groups want to take the risk?
A blood donation center needs zero insurance contracts and does NOT need to belong to any medical groups, as the donations are free or the pt is compensated a little bit, but the donation center sells the donated blood to hospitals, red cross, etc.