Shoes is the 2nd item unlocked in the Fashion Store. The Fashion Shop is unlocked at Level 19, the seventh commercial building to be unlocked.
Shoes can be produced in 240 minutes (4 hours) in 2 stages without using the Global Trade HQ or a Speed-Up Token. Based on this production time, the simoleons/minute is 4.08. (High-tech Factories and 3-star shops were used for these calculations.)