Mate #- probably somewhere around $2000 (or a bit over) for a good one - I think my Oceanic for a 4.1 Poly was around $1500. #Can get them for a bit over $1000 or an individually designed and crafted aluminium one for 5 or 6K.
Same old same old, you get what you pay for (on a good day)
Have a look at this URL:
http://www.seamedia.com.au/pdf/previ...ALER2_prev.pdf
The article is called something like "What the Dealer Meant to Tell You About 5.0 Metre Boat Trailers, But Forgot"
Also you could search a string like "best boat trailer" on Australian Google. #Or do a Search on this site.
FWIW
Tony