Databases are an asset to a business and commands value.
If you are personally involved or live in an area where you are selling your business you may want to sell it to a company you trust but generally businesses will try to place a value on their data. Afterall they worked hard to build it in the first place. Here you have a guy who has 'cold called' you and called you back sometime later as if it was the first time he had spoken to you. No doubt you are right to think that he is calling around trying to off load it to whoever. Dispite his accent which bares no relevance.
In addition there are a lot of small businesses or sole traders out there who are desperate to find a list of names that they can tap into to kick start or expand their business who may fall foul to a list of names that may have no value.
I agree with the previous post you have nothing to loose by asking for further details such as, how he heard of you, how long has he been trading, potential annual turnover, where is he based etc.
It is reasonable and so easy to become suspicious when people do not do as they say they will especially when he did not send you a confirmation email the firsts time at your request. Therefore you might ask yourself if selling his list of contacts is so important and geniune or just a con.