Salesforce Software Development Engineer In Test (SDET) interview questions

I was given task to write complete automation script to automate end to end feature using Selenium. I completed that on time and wrote complete Page object Model framework along with Testng. After that I had code review for same framework which went very well. After 3 days I received call from HR mentioning that I have been selected for the position and discussed about the offer. now, what logic is that when company like Salesforce offering me CTC which is lesser then my current CTC, I am working on same package from last 1 year and reason I got that is we are offering you only AMTS. I understand that profile differs from organization to organization But how can someone join on lesser package ? if they would have told me that you have to work on less package I wouldn't have wasted my 3 days in writing and developing the framework.