Check this analisys of a guy who used their service:
AppGratis - $2,000 Unincentivized installs - Weatherback Weather Wallpaper
I am surprised someone is willing to fork out 2K for a service they have not used them before. If this is first time you are using their service, always try small if they allow. This is simple logic isn’t it? Why commit so much when you never get a trial before?