That remark about the "co-pilots" salary is not true. There are a lot people hired to be a captain and getting a probationary captains salary, which is slightly lower than a captains salary but much better than a copilots salary.
Netjets is not "fuzzy" about the salary, but they need a detailed breakdown of your hours to give you a quote (PIC, jet-time, multi etc.).
When you pass the selectionprocess, you'll get a job-offer including the salary they offer you. It's then up to you if you accept it or not.