May have gypped my own pay rate

I applied for a job on Monday with a really cool company doing what is essentially Help Desk work with some SQL reporting. I got a phone call on Tuesday, and then three successive interviews on Wed, Thurs, and Friday. I did some preliminary research on payscale for the job title they were actually using (Data Analyst) and found the pay rate to max out around $18/hour in that area.
I thought to myself that it was a pretty huge step down from what I'm making as a freelance codemonkey but it'll get me in with a great company in the industry I'm going for and the COO mentioned I could grow into my dream job from within. "Let's do it!" I said to myself.
Interview progresses well and the HR director asks what kind of salary range I'm looking for. So I start what I thought was high for the position - $45k/year. She immediately agreed and I got sent a job offer. I accepted primarily due to all the benefits about the job. (It's in the right industry, I can work towards where i want to be in the future, It's back where most of my family/friends are, etc.)
To those more familiar with HR personnel - did I go too low? Every other "employee" based job I've had required some haggling.
I thought to myself that it was a pretty huge step down from what I'm making as a freelance codemonkey but it'll get me in with a great company in the industry I'm going for and the COO mentioned I could grow into my dream job from within. "Let's do it!" I said to myself.
Interview progresses well and the HR director asks what kind of salary range I'm looking for. So I start what I thought was high for the position - $45k/year. She immediately agreed and I got sent a job offer. I accepted primarily due to all the benefits about the job. (It's in the right industry, I can work towards where i want to be in the future, It's back where most of my family/friends are, etc.)
To those more familiar with HR personnel - did I go too low? Every other "employee" based job I've had required some haggling.
Comments
I might do that.
Everyone - If it sounds about right it's probably about right. I'm just not used to it
Still, all the perks involved outweigh any problems i have with the wage itself. I just want to be sure I'm being paid appropriately for the area/work.
Thanks guys.