In my experience...
Gold titled shipwreck items are the ones that are considered prepatch and thus 'rare'. The below information is for the prepatch gold titled versions. Current shipwreck aren't worth much.
The pillows aren't that uncommon with the rectangle ones the most desirable decor wise. Paintings you can find pretty easily as well and they can be turned with a deco tool. Blue lady gives the red lady when turned. The large painting goes for the most. Shells are pretty common although the nautilus is the slightly more expensive of them. In my experience.. the clothing can hard to find (sandals, skullcap etc), if they have the (blessed) prepatch tag they can go for millions. The other items can go for a decent amount in my experience like the unfinished barrel, stool, globe, bone piles, body parts etc and are less common than the shells, paintings and pillows.
These items are a great beginner collector item as you can start collecting some of them for under 25k. Hope that helps ya out and good luck!