Are we sure he's overrated though? The man is 22 years old and leading the line for Brazil. His hold-up game has improved by leaps and bounds, and he has always been a class finisher. He is incredibly strong and has surprising mobility for a man of his size. Sure he is not rapid, but not too many strikers of his size are, and he has HUGE potential. Taking a player straight over from South America is always a risk, but with the striker market as inflated as it is (Carroll 35 mil, Torres 50, Falcao 36, etc) , it may be a wise one to take. For every Falcao there is a Keirrison, but I think that, at this stage, LD is worth the outlay. At the very least, he'll always be able to score goals at a slightly lower level and he's young, so he'll still have some value even if he struggles. I honestly was unsure about LD until the last six-eight months of listening to Tim Vickery talk about his massive improvement. Nobody has their finger on the pulse of Brazilian football better than him, IMO.
Honestly, if the price is around 18 million euros, who would you rather get? Don't think that kind of money is going to get Lewandowski (also doubt he'd come), and would get us nowhere near Falcao, Llorente, Hulk, etc. I like Adebayor, but for 180k per week, you are going to end up paying much more than the 5 million pound transfer fee for a player who is deprecating in value. Honestly, I'm not sure Damiao would come anyway, but if we ended up with him and a cheaper alternative, like Abel Hernandez, Victor Moses, or Daniel Sturridge (not my favorite by any means), I'd be pretty happy with our options.