my husband was a biker before i was. I liked to go hiking and then he got plantar fascitis and couldn't. so one year we really just sat and glowered. i realized that if i wanted US to be healthy ONE of us was going to have to change. and i asked him to train me for the STP double century.
Spending? I really tried to bite my tongue through most of his expeditures (why do you need more than 1 pair of bike s horts? why do you need more than 5 jerseys?) you need ANOTHER pair of gloves? your bike needs a WHAT?
we could open a small store with all the tubes and tires he's purchased and i have no idea if ANY of the tires not on the bikes are any good.
but now.. here i am... you're going to the LBS? can i go too? I need a new mirror for my bike, and some socks, and i just want to check out the jerseys...
but to answer your question: here's some responses for you:

Look how nice I look! if you let me buy this cool saddle, it will enable me to continue to shape and harden these legs and keep my attitude good!

I could be buying (fill in the blank here) instead!

biking is a healthy habit!