You're not just paying for an office though. You're paying for independence and quality of life. One office (the one you build in your yard) isn't the same as another office (30-180 minutes away, owned, maintained and wholly controlled by somebody else).
- in some countries, dedicated home office rooms and supplies can be deducted from taxable income or lead to other forms of tax reduction.
- you do not have to pay for the commute. Not only in terms of money (gasoline and car value loss, public transport ticket...), but also generalized cost (time lost, loss of flexibility...)
- some employers actively provide financial support for home office (e.g. by subsidising supplies).
I am personally happy to pay for my home office _and_ accept a lower salary if this means I can spend tine with my kids and wife every day, rather than waiting for the train in the rain.
