You generally have two broad quality levels:
- good, basic arrows that function according to the basic rules.
- better arrows that get bonuses (from your D&D-era Arrows +1 to the varying enchantments, warheads, and materials available in GURPS (some since way back in 1st edition with GURPS Japan.)
If you need more of the first, just go the store in town and get more. They're all good - or are they?
"I [. . .] went to a weapons dealer at the far end of town. There I grudgingly bargained with the surly dealer [. . .] I only stopped when I'd selected two dozen more or less decent arrows from the three hundred he had on offer. I had complete confidence in ten of them, while the remaining fourteen were of middling quality, but they'd do in a pinch.
- Alexey Pehov, "Chasers of the Wind"*
For a high-fantasy game or a dungeon bashing game, I wouldn't really do anything to reduce the quality of basic goods. But in a game where gear is king, and the quality of each of your weapons is a real thing to be concerned over and fuss over, it could be interesting.
In GURPS, you can simply add cheap arrows (0.4 CF, -1 to hit, -10% range) to good (base cost, no bonuses/penalties) and fine (+1 damage) or balanced (+1 to hit). Make arrows you make yourself good on a success, cheap on a marginal failure (say by 1-2), and balanced on a critical success.
Again, unless you're playing a game where arrows aren't used by the bucketful (say, 4 per second by a Great Hasted Heroic Archer) and where every shot counts . . . why not consider making the quality of the arrows matter along with that of the bow?
* Sadly, book one of a series but only book one has even been translated to English. My Russian is never going to be at the level of reading the others, and I suspect sales didn't justify translating the others.