One shilling (12 pence), or around a week's wages for a labourer. A sheaf of 24 arrows would cost an additional 10-18 pence, depending on market trends.

As to the time to produce a warbow, there's some evidence to suggest that large scale production involved journeymen who turned out rough bows done by rote, which were then handed off to be refined by the master bowyer. Working this way, estimates from modern bowyers suggest that a livery bow (bog standard bow provided by the King) could be produced in not much more than an hour.