I used to buy list for around £100 per 1,000 numbers. That was business to consumer marketing. Have a look at MediaLab’s website for an idea the types of ‘targetted’ lists that are available. But that sort of carpet bombing approach needs low costs and high value per sales to make it worth while – call centres, diallers, high volume etc
And you absolutely need to check against the TPS register first.
Like all marketing, there are good guys and bad guys – calling me at 7pm in the evening trying to see loft insulation or PPI Claims services from an office in Spain isnt going to work.