There shall be levied in accordance with the provisions of this Act, -;

(a) a Value Added Tax hereinafter called VAT on the sale or purchase of goods by a dealer; and

(b) a turnover tax in lieu of VAT on the taxable turnover of sales of every retailer registered under this Act, whose annual gross turnover does not exceed rupees fifty lakhs and dealers of any specific class or category as may be notified under section 16.