I think the saving accounts in 1999 were maybe 3% a year which would be closer to $900 a year on $30,000 deposit or $75 a month
It is known as non-existent or a scam.
$3k a month is $36000 a year and as a return is 36000/30000 which is 120%.
So basically you could borrow $1m at 10% and multiply your income by 12.
Your Mother remembers wrong...(you should keep an eye on that...)
In 1999 my mother remembers my grandmother opening up an interest bearing account at a bank. She invested $30k and received $3k per month. It was mandatory that there be at least $10k in the account. Of course hard times hit so all the money had to be pulled out and used. Mom doesn't remember all the details of the account but we were wondering, what kind of account is this?