Be aware that there is a big difference between what many dealers call an equalizer hitch and the real, genuine, (note spelling)
Equal-i-zer hitch. Many people call any WD hitch an equalizer hitch. Check with the dealer to make sure of what he is talking about. I would almost bet he is talking about the generic WD hitch and not a real Equal-i-zer.
In any case, that sure seems like a steep price to me. Here in the states you can purchase an Equal-i-zer for about $450 and a generic WD hitch for around $250. The link given a few posts above by Westend to PPL is a good one.
Barney