Certification to Choose PMI / AACE

Hi,

I have been in Planning & Costing for 4 years. I do QS also. I would like to go for certification to work with global employers.

I did a small study and compared different institutes and their courses (PMI / AACE / PRINCE2 / IPMA / AIPM).

I filtered PMP & PMI-SP (by PMI) and PSP & CEP ( by AACE).

but the cost involved in maintaing the certification force me to go for only one certification.

Which one should I choose ?

My requirement is

1. The course should have been able to pass by self study
2. It should not take our savings for maintaining the certification.

Please advise.

Thanks & regards

Badhru