2009 Honda Accord maintenance

I assume you have the 3.5L V6 engine? Yes, you should have the timing belt changed, as well as the tensioner, idler, and water pump. This is an interference engine, and will incur serious damage if the belt fails, either due to the belt itself wearing out, or due to a failed tensioner, idler, or water pump. $900 is not unreasonable for a professional mechanic to do this job.