You should definitely ask them the following questions:
– what exactly will the $4,500 get you?
– ask for a list of things they will do for that money.
– is there a refund if they aren’t able to license your idea?
– how many products have they tried to license and how many have they actually licensed?
My guess is that less than 1% of all their projects ever get licensed so they make most of their money by charging people like they’re trying to charge you. Maybe they don’t even try too hard to get anything licensed.