Doesn't sound un releasable depending on what they are offering, but cost can very wildly depending on allot of site factors and services. But I would be getting as many quotes as posable and getting a complete brake down of what is offered in that price.
Do you know what the exact heating and cooling input requirements are for you equipment ?
are you allowing future for expansion ?
do you have the required power, water, and gas/fuel, on site ?
is there any existing infrastructure on site that needs demo or up grading ?
what is the site access like are they going to require a crane or special heavy equipment ?
what is the supporting equipment included things like tanks, pumps , hot wells, blow downs, ?
was engineering services included ?
those are some of the questions you need to ask