First payware aircraft to buy....

Avoid the Flight1 ATR. A non-native aged FSX addon is not what you want to experience with your first payware. The CS 727 is also a poor choice because of all of the bugs. Captainsim probably shouldn't be your first payware company experience either...Get the PMDG J41. It is one of the best addons available for FSX. PMDG is MUCH higher fidelity than CS, and the J41 is a much newer and better addon than the ATR. They've also got wonderful support right here on the AVSIM forum.