Sorry but I don't follow the logic of the OP Howard Jones.."that in the digital age it's up to the consumer to decide what something is worth".
It has always been, correctly in my view, for the producer to determine a price for the product. Only he knows the real cost of production and of course the correct level of recompense for artistic contribution.
Yes the cd only cost a few pence to replicate but that is the smallest part of the process.
To answer the original question I am happy to pay around £10 for a CD I want. I have just paid nearly £20 for an L.P. I have been after for years.
As a founder member of a record production company (sounds grand!) I have always believed that it is just as dangerous to undervalue your product as it is to overcharge.
But remember it is the performance and the talent of the performer you are buying the right to enjoy, the value of the plastic and the machinery is meaningless.

Andy