Buying bitcoin fee is around usually around 10%-25% depending on the ATM. Some ATM have 3% fee. There are a few different brands.
Selling bitcoin is 0% fee.
What country are you talking about btw? I've just found an article that lists the average fee on Bitcoin ATM's and it's nowhere near the percentage that you mention.
The average fee on Bitcoin ATMs in 2016 was 7.5% and 923 machines were tested in total.
Usually the fees are below 10% and I can't imagine anyone paying a 25% fee to buy Bitcoin.
Source:
https://coinatmradar.com/blog/bitcoin-atm-fees-2016-revision/