Most of my articles are written based on questions asked on this forum and some mails I received.
I have 20 reasons why the rates will defer read some and check th rest here--

http://www.buildingcontractorsecrets.com/2008/09/how-to-determine-your-consultants-rates.html

A subscriber recently asked me to quote for a project and he made mention to me that he will go for the cheapest so my resolve to write on this topic.
Yes it is good to go for a really cheap job but there are disadvantages of doing that which I may write about another time. In otherwords the cheapest moneywise may not really be the cheapest valuewise.
Most often your projects are the reflections of what you paid for, below are why you may have variations in fees from your consultants-architects,lawyers,QS,Structural Engr e.t.c
These are what will determine the fees

(1) Experience-
The Experienced consultants work hard to stay ahead of the curve learning new trends and skills that benefit customers. Some have spent more years in the job than others, hence you may get a better job from them to the less experienced though not in all cases, expect to pay more to such people.

(2)Location of Consultants-
Running businesses in the area your consultant is presently will affects how he will charge you. If the office is in a high brow area don’t expect less from him, he needs to pay for the rents which usually costs more, and the thinking of the average Nigerian is that if your business is in such area you must be successful and experienced, again which may not be always true.

(3)Location of Project-
Where your project will be sited will determine the fees the consultant will charge. Imagine you want to build a 4-bedroom bungalow, but you bought the land somewhere in Ikoyi close to N100million naira, now for somebody somewhere I can afford to do the design for that person for N20,000-N30,000 , but for someone that bought the land for that price count me out I won’t agree to take anything less than N200,000 for the same work, same energy and same product, so also have this in mind.

(4)Influence or Name of Consultant-
You’ll agree with me that how well known a consultant is can also determine how he will charge you as the client.
For instance Festus Keyamo,Gani Fawehinmi e.t.c may not really be the brightest brains in the legal profession but for the mere fact that they are well knowned, you will be surprised if they ask for a low fee for your job and that also reflects in every profession.

(5)Closeness or Relationship with Clients-
The relationships between you and the consultant will determine what he is likely to take, he may even do the job for you free, if he is your brother or a close friend he won’t charge the same with an outsider.

(6)Level of Education-
If he has recently gained new certifications, or additional professional credentials that help clients, that knowledge has value. There are professionals with high qualifications with all manner of certifications, expect to pay more to such people.

(7)Office Settings-
How plush the office is will determine the fees also, if you are ushered into a reception that worths millions of naira and is very clean and organized then don’t expect anything less from the consultant, your money has got to maintain that plush office, ready to pay more. Other consultants are operating from home so they may charge you less.

(Consultants numbers of Employees-
Have you entered an office and the C.E.O is introducing you to everybody in the establishment? He is only showing you around to let you have a fill of how big the company is. So after showing you around and you discovered that there are a lot of employees working for the man, then expect to pay more to maintain the staff.

(9)Consultants’ Controlling body-
The association of each profession atimes regulate how their members charges customers/clients to help protect themselves from been underpriced. From ordinary barbers in the street to big time consultants, the story is the same.

(10)Government Policies and Regulations-
If the government of the day gives zero tolerance to quacks then expect the fee of the few professionals available to be very high.
If government gives regulations that makes the job difficult for your consultants they will also pass the stress to you in terms of money you will have to pay.
Continue -- http://www.buildingcontractorsecrets.com/2008/09/how-to-determine-your-consultants-rates.html