Here in Canada, the price of the bitcoin is approx $3,100 Canadian dollars. However, the ATM gives you a rate of approx $4,100. I deposited $100 and got back $77 worth of BTC. Is this the normal rate?
Different services, exchanges or atms have different rate and or premiums for buying into bitcoin.
For your case, assuming 1 BTC is $3100 , but the ATM has a higher premium of 1 BTC for $4100, roughly what you should get will be 3100/4100*100 or 75.6097561 CAD roughly.
I am pretty sure there are other exchanges which will give you more btc for $100 cad