How much did a hand-copied book cost in the Middle Ages?
The record: ≈ 18s, 1397.
About $2,600 in today's gold
108 days of a farm labourer's pay.
126 books bought for £113; a 15th-century Peterhouse copy itemised parchment 6s 9d, copying 36s, illumination 8d, binding 2s. Source
Who could buy it
The lowest paid on each ladder of 1350 whose pay was enough:
On a day's pay
On a week's pay
On a month's pay
In other words, dear: months of work for a farm labourer.