Looking for COMFORTABLE shoes, please help.?

I am looking for nice, comfortable shoes for a upcoming trip to paris. I have tried so many different shoes but I keep sending them back. I am looking for something other than tennis shoes. I would like more along the line of ballet flats. I have tried the puma ballet flats (http://www.shop.puma.com/Women/Footwear/Ballerinas/Espera-II-Ballerina-Flats/pna884629144464,en_US,pd.html?cgid=13120) these are the ones that i tried. I had to send them back because they were so uncomfortable! I have all these nice dresses that i bought and i would prefer to not have to wear sneakers with them. ha-ha. A problem im having is I wear a size 5.5. I can fit into a 6. but its kind of big. I would like the price to stay under 150. Thanks for the help.