If you are looking for a cheap and efficient way of travelling from Suvarnabhumi to Pattaya or the other way round i can thoroughly recommend Bell Travel Service. They offer door to door service from the Arrivals Hall in the Airport direct to your hotel or to the Pattaya North Bus Station. In reverse they will collect you from your Hotel in Pattaya and take you to the airport. All for the bargain price of 200 baht each way.
Transfer time is approx 90 minutes. A truly excellent service.
Here are all the details....
Bell Travel Service Co Ltd
Bangkok: 084-427-4608, 02-747-4675/6
Pattaya : 084-427-4607, 038-370-055
Departure Times from Airport, Level 1 Gate 7...
0800,1000,1200,1400,1600,1800.
Departure Times from Pattaya.
0600,0900,1100,1300,1500,1700,1900