Dear Mr. Venkat,
Nothing is called simple or easy. It all depends upon the lawyer whom you are approaching. There may be many lawyers who may not even undertake such jobs. There may be lawyers who will do the job free. There may be lawyers who may charge very very less compared to others. It all depends upon the standing of the lawyer.
If you think it is so simple, even you yourself can get the same registered. There is no need for the assistance by lawyer at all.
A lawyer commands his fees based on his experience and the confidence that he arouses in his client. For example Mr. Harish Salve charges a fee of Rs. 2.5 lakhs and above for a conference i.e. meeting. Other lawyers of lesser standing may do the meeting free even if the meeting takes place for one or two days.
You are absolutely correct - you will afford only what your budget permits. For this you have to really approach a number of lawyers and find out what they would charge and then take a decision.
Similarly, the lawyer will undertake to do a job only if he is satisfied with the fee that he would be getting.
The long and short of the story is, it is sheer bargaining - from both ends. There is no fixed schedule rates as far as the lawyer's services are concerned.