關於offer, need help.

上周五on-site interview, 剛才（周一），hiring manager called and said he would like to move forward. He asked if I would like to accept an offer that is one level below the one I applied and interviewed. He said that won't be financial impact, just a title change.I think there always a finance impact in the long run. He said he will move it over to HR for further process if it is OK with me. During the phone call, I sort of OK'd for the lower title offer, but sticked with the salary range I asked.
After the call, when I think about it and am not very comfortable. Is there still room for discussion and hopw should I approach it? I don't want to loos the opportunity, however if it is lowered down, I am not better off much compared to my current job.