The amount of assistance which any person shall receive shall be determined by the Commission with due regard to the resources and necessary expenditures of the individual and the conditions existing in each case and in accordance with the rules and regulations made by the Commission and shall be sufficient, when added to all other income and support of the recipient, to provide such person with a reasonable subsistence compatible with decency and health. In determining the need of a person who is blind Commission shall, in order to provide an incentive to rehabilitation and self-support, disregard the earnings of a person who is blind to the extent of $150 per month and 50% of the earnings over and above $150 per month, provided, however, that such earnings shall not be so disregarded if the effect thereof would be contrary to the requirements of the Federal Social Security Act [42 U.S.C. § 301 et seq.] as amended. In no case, however, shall any person who is blind receive assistance from the Commission in excess of a maximum set by the Commission based on the amount of funds available for assistance for any given period.