Hey,
As far as I understand it:
Boosting is safe when the customer doesn't log in during the boosting session. This makes sure Riot doesn't detect 2 IP addresses from different locations logging into the account in a short time frame. It breaks their rule of account sharing. If there is also high ranked winrate alongside this it considers it boosting.
Using a VPN and offline mode helps aswell. VPN makes sure the boosters IP is in the same country as the customers IP making it less suspicious. Offline mode helps if you got friends that chat a lot and maybe figure it out and report you lol.
Anyway I can do G5-P5 for 35 euro total paypal. Can go first a few games to prove I am good enough for the job. Will also use VPN and offline mode. Finish in about 5 days max.
If interested contact me here or on Skype: SS Boosting