If you want to build efficient, cheap list that is really good in competitive enviroment I would go with the following buys:

Imperial Aces x 1

TIE Interceptor x 1

TIE Advanced Prototype x 1

Starviper x 2 (Autothrusters!!!)

A-Wing (Push the Limit)

This way you can make great Imperial Aces list with Soontir, Carnor Jax and Inquisitor. It is really fun to play and will teach you a lot about playing X-Wing.

No A-Wing needed, Imperial Aces has 2 Push the Limits.

But with THREE Interceptors some will think all of them need to be packing PtL. By that same token just getting a single StarViper gets you 2 copies of Autothrusters; 3 can certainly be nice but while it may want to stay out of arc Jax's ability is one that asks for him to get well inside of that R3 requirement.

A better solution may be to see if you can find someone who purchased multiple Interceptor expansions (which isn't nearly as common since Imperial Aces came out) and see if you can cheaply take the "extra" Fel card/base tile off that person's hands. Besides Fel and Turr what does one get Interceptor Expansions for unless they want to try swarming with the Alphas.