Thanks for clarification. I wasn't sure what the '20' was in your calculation, but it makes a lot more sense now.
Still, I wear Nikes, and paid $7 for them at Goodwill. Used shoes. Sure, people will not like that, but used Nikes is a lot better than new sandals for my purposes. I've been wearing the same pair now for years. It's about time to get some new ones. New to me, at least.
Thanks!