H1B1 extension question!!

I am in green card labor pending period and also going to extend my H1B status. In order save money, I want to do H1B extension myself, but have a question to prevailing wage in H1B labor application form:
According to Dept. of Lab website, the prevailing wage of my position is $85,000 and $50,000 for level 2 & 1 respectively. My current salary is in between. My green card labor application requirement is MS + 2 years, which is level 2. In this case, what number should I fill in? If $50,000, does it affects my green card application negatively? My salary is less than $85,000, can I fill in a number between $50,000 and my current salary?

Thanks for your answer!