Can't afford to lose money by buying a ticket before I have a China visa. Will an itinerary do?

I have an official letter of invitation and wish to apply for a Tourist L type. On the application form it asks for travel details, but I cannot afford to buy a ticket beforehand in case my application is refused, and then I can't get a refund. Also, if I book a ticket now the visa may not arrive until the intended travel date has passed. I intend to travel in March. Would a rough itinerary suffice or do you have any other suggestions.