Business valuation is a very subjective area. This is perhaps the most important step. Realize that you can develop the skills to do business valuations just as well, and probably better than anyone else. It isn't necessary to have a certificate by an organization to be a business valuation expert. Don't be afraid to tell your client that you can do his or her business valuation.
Business valuation is a very subjective area where judgment is the most important factor.
You probably know your client better than anyone else. This makes you, rather than some outsider, the logical person to do the business valuation. Your knowledge of the client is also a key to making money doing business valuations. This will take time. Your bid for the valuation can be competitive with the outsider's bid, but you won't have to spend the tremendous amount of familiarization time that the outsider will.