You're not going to get much for it in most markets - "only getting mileage" would be gas costs. In other words, doing it for free.
In the current area I'm in (Mobile, Alabama - I have a couple friends who are Realtors) most of the agents are taking their own pics or getting a friend with a camera to do them. However, out in Los Angeles, where I used to live and still have a lifelong friend who is a Realtor, people are still getting paid hundreds/low thousands of dollars for real estate photos, but again this market is still going strong selling multi-million dollar homes.
Here in Mobile, the most expensive homes are about $500,000 and even those are few and far between because all the new development is low income and you don't see expensive homes for sale often. One of the friends sold apx. 1.2M worth of property last year, and only got like 50 grand of it. The agents are responsible for photos, so that would take like half of her yearly income away if she was to pay someone. But in LA, where the other friend is selling 10M a year and LIVING in one of those homes like she's often selling, she's paying a photographer.
If you're in an area where the market's in a downturn, good luck finding ANYBODY who will pay you. But if you're in a high income, high population, and good market then you can still thrive off the business.