A little vague. How often do I lose my mini? Well, I can't say "never", because it's perhaps once a year or every few years, but "sometimes" seems an exaggeration. "Rarely" would be a good answer, if available.
Count me among the non-market for custom minis. I have handful because I carry 2 in my bag (1 as a spare), and occasionally receive one in players packs. I have a custom mini, but only because it has a very specific stamp on it---and otherwise, it's a run-of-the-mill, baseline Innova mini. No other stamp or print is going to interest me. (I once had a pretty tie-dyed champion-plastic mini, but it squeaked loudly when I stepped on it, and you don't want a foot-fault tattle-tale like that on your team).