At 50 euros a vote it's clear an organisation is needed to market them for a meaningful return. Individual vote-selling wouldn't be worthwhile. Step forward the Mafia, more specifically the 'Ndrangheta which has exported itself to northern Italy (or quite possibly gone global) from its historical haunts in Calabria (that's Bari, and its hinterland, as the Ryanair announcement "Welcome to Bari, Mafia city, please ensure you have all your belongings from the overhead lockers with you." noted.)
It used to be that votes were bartered-for individually - right shoe before the election, left shoe once the candidate was returned - so more or less the price is holding steady as the exchange becomes more sophisticated. The price of shoes once determined vote prices in Naples (and now Lombardy) rather as the price of a gramme of gold determined the price of a decent lunch in Florence.
Berlusconi's PdL rightist party executive councillor Domenico Zambetti is accused of giving 200,000 euros for 4,000 votes to the criminal organisation for the Lombardy regional elections in 2010, and now joins 13 other councillors of the Lombardy regional Executive and Assembly under criminal investigation. This includes their leader Roberto Formigoni , a crucial Berlusconi ally, who is accused of health contracts' corruption and is expected to resign later today.
It does cross the mind that the manner of compiling electoral registers in the UK lends itself very well to vote bundling and sale; who needs the Mafia when registration is done by household? Yes there will be IER in 2014 but it's neither comprehensive nor effective.
The price of a vote in England used to be expressed in beer so it's quite hard to establish where UK vote-prices are now, both because of the variability in how much beer is needed to get a voter dead drunk and the teetotal habits of many of the bundled voters.