I admit to having had eyelash extensions for 2 years. I paid $200 for the first set and then paid $40 every three weeks to have them touched up (plus $10 tip). I justified it by comparing it to my friends who got their nails done just as often paying pretty much the same thing for that. I loved the extensions... they looked great and I never had to worry about makeup. Having them saved me time getting ready every morning and I really liked the way they looked.
I stopped having them done last summer when I realized (way before finding MMM) that spending almost $700 a year for something like that really wasn't a good use of our money. Granted, sweet DH and I make a ridiculous amount of money, have no debt outside our mortgage, and live well below our means. This was my only "personal treat" expense but it was still a big expense.
We had been planning an early retirement in June of 2018 when we would be 55 (the magic age for 401K penalty-free withdrawals) and 54. Since finding MMM and reevaluating ALL of our expenses, we've since moved that retirement date up to November 2015, over 2 1/2 years earlier!