what are the the costs that a lawyer suppose to charge by law

The agreement between an attorney and the client is largely a product of the private agreement between the attorney and the client, subject to a few restrictions under the Rules of Professional Conduct.   Pursuant to NRPC 1.5(a), attorneys are prohibited from collecting "an unreasonable amount for expenses."   The basis of the expenses for which the client will be responsible shall be communicated to the client, preferably in writing, before or within a reasonable time after commencing the representation.  Any changes in the basis of expenses shall also be communicated to the client. NRCP 1.5(b).  If the fee is contingency, the agreement must be in writing and signed by the client and must state (amongst other things) (1) whether litigation expenses are to be deducted from the recovery and whether such expenses are to be deducted before or after the contingent fee is calculated; (2) whether the client is liable for expenses regardless of outcome; and (3) that, in the event of a loss, the client may be liable for the opposing party's attorney fees, and will be liable for the opposing party's costs as required by law.