Exchange rates are reference points, not offers. This guide explains the forces behind the numbers you see.
The Saudi Riyal Fixed Exchange Rate
The Saudi Riyal (SAR) is fixed to the US Dollar at an official peg of 3.75 SAR per 1 USD. This fix means exchange rates for SAR against secondary currencies move in exact lockstep with US Dollar fluctuations.
Using Digital Cards vs Cash in Makkah and Madinah
Modern retail outlets across Saudi Arabia widely accept contactless visa/mastercard payments (Mada). Carrying multi-currency cards reduces cash exchange markups experienced at airport currency booths.