i had terrible foot pain after only riding 8 miles, so i went to a specialist and ended-up with customized orthodics. on my 2nd pair and it has made a world of difference!

note: my feet hurt on other occassions, not just riding, but it was the riding that inspired me to get my feet checked-out. if your pain is only riding, it may be 1). just getting used to set-up, 2). cleat placement, 3). extra support for riding -- met lifts are excellent!, or 4). fore/aft position and riding technique -- if you are too forward you could be mashing; to far back you could be stretching/reaching which may cause feet issues.

just thoughts ...