I changed out the 4 tubes this season on my 2006 228.
Problem is that they have slightly changed the design or the rod holder and tubes and don't have any of the old version left at the plant(I placed several calls to the manufacturer that were never answered/returned). Your tubes are probably solid like on my 2006. The new ones have access holes to simplify the installation process. Problem is that the new spacing of the horizontal members changed, so the holes won't match up with your existing hortizontal elements. IMO it looks better than the old cracked tubes but not as good as Original.
The tubes themselves are about $5 per tube from any Grady Dealer. I am in Savannah, GA but have always ordered my parts from Port Of Egypt marine out of NY. I will be at my boat today and can take a pic if you would like.
Padgett
Mixin'ItUp
Savannah, GA