I recently graduated and am looking for a full-time position. I was interested in a small local start-up company and did some unpaid demo work for them to show them what I had to offer.
After the demo work they offered me a job in the company saying that they selected me over other candidates on the strength of my demo work.
The salary they offered is lower than what they usually offer candidates for that position with my education/experience (based on information from a friend working in a similar position in that company). I am worried that they may be offering a lowball offer because I showed so much enthusiasm and a willingness to do unpaid work for them. I am interested in the position, and would be happy working for less than what I've been told is their standard offer, but would like to negotiate a slightly higher salary than what they initially offered.
When faced with a lowball first offer, is it possible to negotiate without jeopardizing their offer, and if so, how should I approach the negotiation?