One thing no one has mentioned is budget.
Are the company trying to offer you the casio on a cost saving basis (this would be a little odd as other 2500 lumens projectors would be cheaper) but as localzuk said the running costs with no bulbs would bring down your total cost of ownership.
I would have thought that you would really need at least a decent 4000 lumen model, depending on budget and the space you are using it in I woud recommend going a bit higher if possible. Just remember generally these larger projectors have more expensive bulbs so make sure to take that into account when working out your budget.
As for the comments on the casio, although there are other LED projectors due out on the market the only one with any definite time scale is the new samsung model (I'm hopefully gettng my hands on one this week will post my thoughts) and that is no where near the spec of the casios.