...More importantly, why exactly would I pay $130-$200 for 'designer' foldable ballet flats that look exactly like the ones I can get at The Gap for $39.50?
Perhaps if I were determined to get a unique color, like turquoise or tangerine, or if I really wanted to have those nifty robins egg blue soles and the luxe gift bag, I'd go with the Tieks (pictured above).
But if I'm happy with basic black, metallic silver/gold, or red, then it seems the Gap's City Flat will do just fine. That said, now that I'm working in the city and walking at least a mile or more every day, I love the idea of foldable flats that tuck into your purse or backpack, rather than the 80s working woman look of bright white tennis shoes + suit. These flats, whether you prefer the high end or the mass-market, are so much more practical and modern!
UPDATE: Thanks to my friend Mario for this tip - there are two new UK companies, Rollasoles and Afterheels, that are selling these kinds of foldable, portable flats...but the genius twist is that the disposable flats are only GBP 5 and are dispensed from a vending machine!