The verification is done once when you are registering a new Gmail account. So the $0.75 is for the verification code received when making the account. After registering with Gmail, the number will be associated with your account for verification and account recovery but I would advise you to remove the link as soon as you finish registering the account and instead link it to other phone numbers or alternative email addresses that you can readily access so that in future when google prompts you to verify your log in, you can easily access the codes through your readily available phone numbers or alternate email addresses.
Ya, thank you! I understood how it worked, I just tried using a few phone numbers there. But unfortunately, whether it's a real US phone number or a US virtual phone number, I can't sign up for Gmail. I have tried more than 10 numbers and all reported that I cannot register with those phone number 
I only need to do the verification once, then change it to another verification method when logged in, so there's no need to worry about it being canceled after 10 minutes. But the biggest problem right now is that US numbers can't be used, I tried with a phone number from another country, it worked, but I didn't need that country
Anyhow, it is also one of the useful services. I registered an account and deposited $ 5, which I can use for any other purpose 
Thank you, logfiles!
Going to lock this topic right now
Post here or send me a message about it. Thank you!