100 is high isnt it.I usually follow accounts that are similar to my industry and then I will go into their followers profiles, see if they have a good following to follower ratio and if I do I will follow them. More than likely most of them will follow back. Just make sure not to do this too quickly (don't follow more than 100 people per hour).
I've done 100 and haven't ever had a problem. If it's a newer account I'd keep it less than 75 but my established account hasn't ever had an issue with doing 100 per hour.100 is high isnt it.
How do I buy the bitter onesYou have a couple of options;
1. You pay for Botted Followers which start at like $1 per 1000
2. You work on your profile and grow organic followers