I used to change strings often just to try different strings. All of my ukes had tie bridges and "normal" head stocks, but I got a new Bacote Tenor last week and after only 2-3 days the A string broke! Now, this tenor has a pin bridge and slotted head stock, so it is a chore to change strings. I'll only change strings on it if one breaks!
I bought a set of strings yesterday for my cedar top Ohana tenor, the strings on it haven't been changed in probably five years. Since it has a tie bridge and normal headstock, I figure it will only take a half hour to change all of them