I agree with Mimitabby on the vacation aspect. It is so easy to blow a few grand on a good vacation (air, hotel, rental car...).
Another tack might be to look at unhealthy habits that cost $$$. I'm thinking smoking and large amounts of alcohol could quickly make bike expenditures pale in comparison.
Cigarettes must be $5/pack/day roughly plus 4 beers a night = maybe $7 a day x 30 days = $210 a month x 12 = $630 a year. This does not include going out to drink costs
which would push the cost much higher.
Plus I figure I save @$3 a day in gas money that I bike commute.
Quill
Yes, SHE can.
"Angels fly because they take themselves lightly"
Gilbert K. Chesterton