As others have said, read your manual and find out what the replacement interval is.
I had the timing belt and water pump replaced on my wife's 2003 Odyssey last year for about $500. This was at an independent shop; Honda quoted me $650.
Go on and have the work done. I know it's expensive, and you think you can keep putting off spending the cash. However, before you know it, when you least expect it, the belt will snap and you'll be in a world of hurt.