No attorney representing a claimant shall charge or collect fees for legal services rendered to the claimant unless the fees have been approved by the board or the superior court, as the case may be. In determining the amount of allowable fees, the board or the superior court shall consider, among other things, the nature, length, and complexity of the services performed, the usual and customary charge for work of like kind, and the benefits resulting to the claimant as a result of the legal services performed.