These two cardboard ships, a warship and a merchant ship, have seen frequent use in D&D games, as well as in an earlier Iron Heroes game. While IH was a different and refreshing variation from D&D, I find it currently too cumbersome ruleswise.
If you want to create yourself cheap small-scale spaceships, you have two options available: Buy or find free papercraft starships, or scratchbuild them. This article shows you basics of scratchbuilding starships.
Materials and rules for scratchbuilding
1. Keep your eyes open; use anything, salvage things
A non-gaming post this time; As readers of this site are mostly gamers, I'll say a few words for this piece's gaming use too; it's not difficult to stretch one's brains to have an idea of using this decorational model as a giant fish the PC's must fight (or can summon!) The model can also be thought a miniature.
Victory-class Star Destroyer is another vessel not seen in movies. It is predecessor of Imperial Star Destroyer, is 900 m long and has seen it's best years during the old republic. Although it's too slow to be too effective in ship-to-ship -combat, it still excels in one area: It is still the largest ship able to enter a planet's atmosphere. Combined with it's heavy weaponry, this attribute makes it excellent ground assault craft.