Two that are marginally better than a practice spear and that are obtainable at the 10th rank (possibly depending on alignment) are the long bone-handled javelin and another one that's a quest reward.
Two that are slightly worse than a jeweled broadsword and that are (arguably) obtainable at the 20th rank (possibly depending on alignment) are the gythka and short spear.
You're right in that they don't grow on trees- those are the only ones that came to mind. It is highly likely there are some I'm not thinking of (or that I don't know about to begin with).
We sell (barter permitted) a limited spear for a reasonable price in an easily accessed location.
While spears aren't the most common weapon by a long shot, the sheer number of objects in the game by now means that any common category is covered to some extent.
