My thoughts are that at £20 million (and we could probably nick him for £18 million) Berahino represents a shrewd buy.
He is young, homegrown, has proven that he can score goals in this league, knows several of our players from his time with the England under 21s and his wages will not be prohibitive. Even if he didn't quite make the grade at Spurs over the next two to three years then I would've thought he would still command a transfer fee of at least £10 million so effectively he represents a £10 million gamble.
From what I have seen of him in the past couple of years he has all of the tools necessary to become very, very good indeed. He is quick, quite powerful, offers good movement, puts in decent workrate, has two good feet, nice balance, is a good finisher and he has a lot of confidence and self belief (which I think is essential for a CF). With the right attitude, desire and coaching I think he could easily become an Ian Wright type centre forward, never giving defenders a moments peace, pulling them around all over the place and getting involved in both the build up and finishing off chances.
Yes there is a question about attitude (the 4am drink driving offence) and also some rumours about poor time keeping (although I notice these rumours seem to have magically started just as it seemed WBA would be prepared to sell him.... their fans trying to justify losing him perhaps?). Perhaps him coming to a club where he doesn't know he is by far the most talented player, isn't guaranteed his place and will have to fight for it is exactly what he needs?
I remember when Sturridge went to Liverpool and there were the exact same question marks about his ability and attitude posted on this board. I think Berahino is at least as good as Sturridge was when Liverpool signed him. It is rare for good players to become available for a reasonable price in the January window, events have conspired for this to happen now and I hope we don't miss out.