Quite often the decision of which compressor to purchase rests in the hands of the company accountant and the 'purchase price' of the unit...
The sales representative will go through his sales pitch to the Engineering or Production Manager, whom on many occasions have an understanding of the equipment and the benefits of the 'brand'. When all this is done, the carefully drafted proposal is sent in and the accountant asks... 'how much ? can you get another couple of quotes ?'
This sometimes leads to poor choices of equipment with price being the mitigating factor of the purchase.
If that is the route to be chosen, then the question should be... 'what is the cost of ownership ?' and not 'how much ?'.
The world leading brands, such as Kaeser/HPC may be higher 'priced' than inferior competitors but their 'cost of ownership' in many cases is less. (more bang for your buck - so to speak)
The only factors should be:
Output/kW
After sales cover (service care and warranty)
Lastly... price
Also, if a sales rep. says, 'this will save you thousands'... ask them to guarantee the savings as part of the contract and get them to prove it.