A cheap ~$20 110V 3 speed mini fan, like this one:
https://www.amazon.com/Honeywell-HT-...dp/B001R1Q2C6/ uses about 2 cents of electricity per day at the low to mid speed setting. (2 cents, based on 5W power draw and .18cent/KwH total power cost). Or, less than $5 for about a years worth of operating during heating season (and that is being super conservative, it's probably less than that).
The fancy $50 and $100 woodstove fans are neat, but they are not really that cost effective.