Go to Wal Mart. In their foot care department where they have the Dr. Scholl's stuff they have "arch supports". These are an off-brand, little Ace bandages that slip like bracelets over your feet. Wear them over your arches and I bet your pain will go away.
I have a friend that had plantar fasciitis and was scheduled for surgery. I told her about these and after wearing them for a few weeks, she cancelled her surgery.
I am not big on wearing shoes at all but these little arch bands can be worn all day, all night, barefoot or with flip flops. They are thin enough to wear with any of your regular shoes, also, and since they are flesh color, they are pretty inconspicuous. I believe they cost about $6. each-not per pair, but that is way cheaper than orthotics or new shoes.
I SWEAR by them. Don't wear them constantly but when my arches first started getting sore I found them and did wear them every day. Wore them a lot at first, now I wear them only when I know I will be on my feet a
lot. Sadly, I have only found them at Wal Mart.
Good luck.