According to the association that represents the pharmaceutical industry in Britain, the shortages you refer to were due to pharmacies taking advantage of exchange rate differences to sell medicines abroad rather than supply the UK market[1]. This would imply that the costs of medicine are not usually significantly lower than the rest of the EU, at least when the currency markets are not in flux.

There is some information available on the cost of prescription medicines in the UK (see [2]) but I don't know where the equivalent datasets would be for other countries. Would be interesting to do a comparison.

[1] http://www.abpi.org.uk/our-work/news/2012/Pages/280212.aspx

[2] http://www.hscic.gov.uk/searchcatalogue?q=title:"prescriptio...