This Iberian WB crap drives me up the wall.
It's a Lusitano crossed with a QH, lets call a spade a spade. Based on breeding alone, it has one half that is likely not going to make a third level dressage horse (the QH half) and one half that depending on the breeding, is potentially capable of doing so. However judging by the price, it's probably some "Lusitano" that's not even in the Portuguese studbook anyways (or wont be for long once they learn he's been crossbred).
Therefore, it's extremely unlikely that the horse is (by breeding) going to even have 2 decent gaits for dressage, let alone 3. Of course there are always freaks of nature, but in general I'd say the horse is destined for a life of pleasure riding and maybe doing some cow work.
You're going to have a lot more success in that price range looking for a nice TB that is capable of some good third level work.
They say money doesn't buy happiness -- well happiness doesn't buy horses!