Is there financial help available for people in need of prosthetic feet?

Insurance. Most insurances cover prosthetics. Go to your medical assitance office and apply iof you can't afford any insurance. Also contact your local state rep if you can't get medical assistance.
To some degree. Some insurances pay for prosthetic feet. If you do not have insurance, you can discuss with the prosthetist about a cash payment plan and discounts. There are some agencies in different states that may help offset the cost. They will likely be income based. Check with your state agencies.