250 a year for a strong photo would be way over. Most photos do maybe 5-10 dollars a year, and strong photos around 100. That has been my experience anyway. I'm sure there are some pros out there who do a lot better than that.
There are different licenses customers can buy, depending on the intended use. For example, if a publication wishes to print a number above a certain threshold, they will have to pay extra. The biggest single license fee I've made was about 50 bucks. Not bad for (somewhat) passive income.
Thanks for answering. I really had no idea it was that low. Seems like there is room for a decentralized crypto-version of the same thing. I hope someone builds one. :)