Is there a cheaper price if I pay for a whole year?

Yes, on most plans. Settings → Plan & billing has three tabs — Monthly, Annual and Pay-as-you-go — and the Annual tab shows the same plans priced for a year with what each one saves against paying monthly. One payment, one tax invoice for the year instead of twelve. VAT is added on top exactly as it is monthly. Nothing else about your restaurant changes: annual is a way of paying, not a different product.