Leave my driving habits out of this!
My tips are more like oil changes. I'm going to step up to a firmer tip.
It's not really the expense, but the need to stay on top of it and/or maybe be without my shaft. I guess I'm going to have to get a spare shaft.
Yes spare shafts are good, not only "in case of an oops" but also they let you play with several tips at once to compare them.
My tip wear is probably less than most because I rotate through about 4 shafts, 3 normal use ones and a shaft I have been using for travel. I am on the road for work 60-80 days a year and I try to play most nights I am traveling so it's a fairly significant time of tip wear.