I was offer positions by a dozen engineering firms and picked the one I liked the most. I was told later by HR (3rd party consulting hiring firm) that they do not negotiate salary based on individual elements (same salary for all interns per year). The salary is competitive for the average, but 40% lower than my usual paid.
My main leverage with this company is that I interviewed for several positions with different managers within the same company. All team picked me as their first choice and made offers; some are still in the interviewing process after I picked this particular position, leading me to believe that they do not have a more qualified applicant lined up after hundreds of interviews.