Looking for Best possible way of Windchill-Teamcenter Integration

We are planning to integrate Windchill system with Teamcenter Enterprise. As per PTC Sales need to buy Windchill external licenses for each user to integrate this systems, which is not feasible at this moment due to project budget limitation.

I am looking for possible ways or scenario of integration in which we don't need to buy the licenses.

Any suggestion will be more helpful.

Thanks,
Devidas