What I'm thinking is that it would probably be best to rate merchants as 10 gp, 100, gp, 1000 gp, or some other power of ten; that rating covers both the typical value of any item they stock and a general figure for cash on hand. For any common item a player requests, if the value is less than the rating, the merchant has 2d6 units of that (one unit depends on how much of a given item someone would normally keep on hand; daggers would be sold individually, torches in bundles of five or ten, arrows in bundles of 20.) if the item's value is higher, roll 3d6-10, so that half the time the number on hand is 0 (out of stock.) If the value of the item is ten or more times the merchant's rating, drop one die (2d6-10.) For 100 x merchant rating or for atypical items in general, there will be one item in stock on a 5+ (1d6.) Cash on hand can be based on a 2d6 roll as well; the lowest die, minus 1, is multiplied by the rating, then the total of the two dice is added.
- Merchant Rating: 1, 10, 100, 1000, etc.
- Common Items in Stock:
- Value < Merch Rating: 2d6 units
- Value < 10 x Merch Rating: 3d6 - 10 items
- Value => 10 x Merch Rating: 2d6 - 10 items
- Uncommon Items, or value => 100 x Merch Rating: one in stock on 5+ (1d6)
- Cash on Hand: sum of 2d6, plus (lowest die result -1) x Merch Rating