The best way to find out what a reasonable fee is for a buyer in your area is to ask your Real Estate Agent or your Lender to provide you with three names of attorneys that they know of who practice in this area. Since each of them would be working with Lawyers on a regular basis, they should know to whom to refer you. Alternatively, ask friends or colleagues who have bought property for a referral.
Call each attorney and ask their fee for a Buyer closing - giving as much detail as you can (Single family home or condo, date of closing, inspection issues of which you are aware, etc.). Then ask who will handle your file - will it be the attorney you are speaking to, an associate, a paralegal, a secretary? Don't commit until you have done your research.
You shouldn't look for the cheapest price - you should look for the attorney with whom you have a rapport and whom you feel will give you the best representation. You might also want to look to see what they say on their website and if they maintain an AVVO profile, so you have some idea as to their qualifications.
This answer does not constitute legal advice and does not and is not intended to create an attorney-client relationship. The law may vary depending on the state in which you reside. It is intended only to give some direction in which to seek assistance.