Some questions for u before u go to a bootfitter.... did the ski boots work well last season ? Did this pain just happen this season ? Does the pain happen in any other shoes/boots ? Look at ur feet - look at pictures and r u abnormal ? http://home.comcast.net/~WNOR/soleoffoot.htm or google it. Have ur feet grown ? Any funny bones sticking out ? Has your arch gone flat over the summer (sandals, flat shoes and walking in sand, hardwood floors can do it.)
Does rolling a tennis ball under your foot help or reproduce the pain ? (This is trying to figure out if u have a foot problem like a tendon trouble or a boot problem). Does heat make it feel better/rel;eive the pain- that means muscle or tendons/ligaments...or if cold makes it better u have inflammation - its been hurt/bashed)
Did u take take out the liners and the insoles and make sure u got the left in the left and the right in the right ? I skied with a guy on holiday for 3 days of complaining and the shop had put the right liner in his left shell - but it had the left insole so it was hard to tell until I took his boots apart.
Do u have the orignal insoles ? They are usually crap - at a good boot shop ask if u can try a superfeet insole (cdn $39 or so) they have better arch support. U may want to condsider it before buying footbeds. But foot beds are the best thing - but u need a good footbed maker . DO NOT go with a junior guy in the shop. Wait for the Sr guy or the guy that does racers or has smarts. It is easy to screw up.
Try some foot exercises until then, Sometimes the boot/foot problem comes from the opposite side of the shell. Good luck