My opinions:
As long as the shoes aren't $20 K Mart special, they should be fine. Get a brand name, and I would say that $40 - $60 is a reasonable price for a pair of sneakers for the type of walking you'll be doing.I also think that good socks are key. I read somewhere that it's better to wear two thinner pairs than one thicker one. Just in case you do get a blister though...
Last trip in September, I took the following:
A straight pin, or safety pin
matches or a lighter
moleskin and/or 2nd skin blister care patches
Dr. Scholl's foot powder
lotion
Every day, I would LOAD my shoes and socks with the powder. I went through a HUGE bottle in our short 5 day stay. Every night I'd put on the lotion. Dr. Scholl's makes a cracked skin repair lotion. I used that stuff. I also had moleskin on my heels.
At one point, I did start to develop a blister. As SOON as I noticed it, I went back to the hotel to take care of it. I used the lighter to sterilize the pin, and put a small hole into the blister to drain the fluid (not to remove the blister, just to drain it!!! TINY hole!!!!). Then carefully and gently, I washed it and patted it dry I then covered it with 2nd skin blister care and a piece of moleskin. I put more powder into my shoes and socks. Don't put bandaids on it because the sweat from your feet will just loosen the adhesive on the band aid and rub causing more blisters. (That's actually how the blister started, I had a cut on my toe that I was using a bandaid for....)
I tell you, the blister had healed before I got on the plane to go home.
I read a lot about putting deodarant on your feet. I tried it, but it didn't work. The steps I just described were outlined in the unofficial guide. (Is it the 2003 that came out in November?)
Hope that helps!