You can treat it as a reward

Allowing you to work from home is a benefit with real value. You will be saving on gas and parking or other commuting costs; your car insurance could actually drop with less car usage and the commute between work and home accounts for about 20% of all car travel. You will save on dry cleaning bills, eating lunches out, after-school child care. That extra time now spent in the car is time you can spend with your family and friends. You will be saying goodbye to road rage, late dinners caused by traffic, and the stress of commuting in inclement weather. If your boss can't swing giving you a raise this year, point out this cost-free option and let him know it would make you just as happy as the extra money.