API 614 lube oil question

[ET50]

We have a dry compressor (API 619), and it requires an API 614 lube system (Chapter 3). I say it requires an API 614 lube system because of what API 619 says. If our system will be installed anywhere in North America I'm assuming it will require an API 614 approved lube system since we will be installing the equipment in API process areas. I was shocked when I received a quote on the price of the system fabricated by an outside supplier. Has anyone here ever designed/fabricated their own system and is it worth considering, or are we better off buying a system that we know is correct and meets all of our requirements? Not trying to be cheap but the cost we originally allocate for the system is 25% of what we'll have to pay an outside supplier. Any thoughts or experiences are appreciated.