Depends on the model.
About £2000 for a standard Coin Front model in fair condition, to £4500+ for a Bird Of Paradise model with working jackpots, front vendors, gold award, and skill stops, all working (see below). Most of these features, even if originally present, have usually been removed by operators over the years; and original spares are very difficult to obtain to get them working again.
The reproduction ones can be spotted because they are standard Coin Fronts and don't have the rotary coin escalator at the top. They are made in the UK by a company called Terrence Powell. Whether they contain any original parts or not I don't know. The same company also makes an electronic version for use in modern arcades.
The reproduction ones are still nice items, providing you don't pay the price of an original! You could contact TP to see what they are selling them for.