Gas, wear and tear on my car, before and after school care, etc. would probably add up to about 7k/year if I didn't work from home in the relatively inexpensive city where I live (Indianapolis). I can't imagine what it would be in Chicago or New York.

There are other benefits to working from home that are harder to measure:

* I cook more when I work from home because I can stick something in my oven during the work day and have it ready at dinner time, rather than getting take out or buying heat-and-eat foods during the week. This saves big bucks on food, and also improves our health.

* My son gets a better education when I work from home because I am there to see when he's struggling with something, and can work with his teachers to fix it (as opposed to delegating homework time to a nanny or daycare).

* I don't have to take off of work to let a plumber in, to care for my son when he's home sick from school, and so on.

* I don't take off when I'm sick, unless I'm falling-down can't-think-right sick -- there's no worry about infecting my coworkers, not being close enough to a restroom, how I'm going to drive home if I get worse while at work, etc..

* I save a lot of time I might have spent commuting, which can be spent instead on my family, a side project, recreation, whatever.

* I'll never lose 1-2 days of productivity to an allergy attack because Joe Blow from marketing who's a pack-a-day smoker keeps popping by my office reeking of the stuff.

All else being equal, I'd take a job with 20% lower pay in order to work from home full time -- assuming, of course, it isn't one of those companies where telecommuters are second-class citizens. Other related benefits (such as being able to build my work schedule around my life to some degree) could knock it down a bit further.

I see money simply as a tool to help me do things that matter -- money, in and of itself, or as a matter of score keeping, isn't important to me.