Thanks for your questions.
For setting up GPaaS, you need to subscribe to any one of our paid packages. The pricing per instance depends on CPU/Memory consumption. I suggest you have a look at our monthly pricing plans for more details on the same. You can keep the instance for as long as you wish since the payments are made in advance. And, you always have an option to upgrade to a higher package should you need more CPU/memory.http://app42paas.shephertz.com/pricing/
To setup GPaaS, kindly refer to this link http://app42paas.shephertz.com/dev-center/gpaas/
NOTE: The monthly fee is not inclusive of the AppWarpS2 license fee.
The free version of S2 license has been capped at 300 CCUs. What this means is, should your traffic increase during peak time, you will not be able to cater to users beyond the 300 cap. However, the paid version of AppWarpS2 license will allow you to cater to unlimited CCUs. AppWarpS2 unlimited has been priced at $2500 per instance.
Hope this answers your questions.