You can find free tips all over on the internet (Reddit, for example). However, there are many "tipsters" I have seen on Bitcointalk that charge up to $150 to be part of some Discord group where tips are shared, boasting win rates of 90%.
Remember, what you are looking for is how many units someone has won in the long run. If their tips were so good, they would use their own tips to get rich, instead of trying to market themselves to you.
If it sounds too good to be true, it probably is.
These people try to scam others for sure.
If someone has a tip, he would be so dump to share it with other people because if more people would start betting at that tip, the odd would start dropping and Bookers will be suspicious of this bets.