There is no way the painted X-walk will last 5 years. I could see that if they used thermoplastic (heat applied and melted onto the street) strips but the water based paints they are required to use will scrub right off within a year.
As for cost it was probably based on the time to tape off for each color and relocate several times. Something like this: 6 intersections X 4 - 6 color striped X-walks per intersection. Since these were custom colors the chances of having 6 different color pots on one truck were pretty slim. Most traffic painting trucks (white and yellow paint) are equipped with only one pot (requires cleaning to place a different color) or 2 pots, so the contractor would have to rinse and clean between colors.
My apologies as I did not take a closer look at the photo and they are in fact using thermoplastic. The 2 guys at the top right hand of the picture are using torches to heat the material.