There are spoilers herein....


After you finish the first part of Umbacano's Quest, where you get the carving, and come out of the ruin, and it's deja vu where you are Indiana Jones and that guy is Belloq, and he asks you to hand over the treasure.... after the battle, the Khajit usually has an ungodly amount of arrows, the quality depending on your level.

I usually hit this quest after level 30 (for the added "I'm going to die at every turn" factor).
At level 30, on the Khajit, I find between 500 and 600 Daedric Arrows and a Daedric Bow.

I did this quest the other night at level 25, and this is what I found on the Khajit:

125 Daedric Arrows
150 Dwarven Arrows
111 Ebony Arrows
128 Elven Arrows
136 Glass Arrows
77 Iron Arrows
105 Silver Arrows
125 Steel Arrows
One Daedric Bow

FYI, for all those looking for arrows in Cyrodil, I have sources in the Shivering Isles as well. I just thought it was interesting to see the numbers and variety being different at levels.

Thanks for sharing with us markswomen!

When Buffy was leveling marksman, she used to carry loads of arrows and not worry about quality all that much. More shots simply meant better leveling, and with illusion spells, she could safely make her foes dance in front of her for as many arrows as it took. Great fun.

As a master of marksman now however, 'leveling' the skill is no longer required of course, and she quite enjoys going to good lengths to conserve arrows, while still doing most of her killing by bow. Sure, she may just cast a skeleton and keep walking when she gets attacked by a mudcrab, but most foes still die by arrows. She normally carries a small quiver of daedric arrows with more available for resupply in her saddlebags. She quite enjoys using spells to immobilize her foes while weakening them to poison, then launching a single arrow with a powerful poison. At her top level of 20, she can (when she chooses) dispatch any foe in the game with a single arrow if preceded by the proper 'softening' spell and using the correct poison. She gets a kick out of how few arrows she can use now.

As a master, I've found that I can one-hit kill almost anything with Daedric or higher arrows with a poison. If I use Ebony, it will take two arrows, which I can still accomplish while sneaking. If I drop to glass however, I need like 4 arrows, and I could possibly get involved in a melee battle, which usually means my quick death. So I pick and choose which arrow to use on which enemy.

EDIT: But yeah, I usually carry an amazing amount of arrows.

speaking of mastering Marksman, I have a question. During the "Marksman Training" quest, once you find Alawen, she won't train you unless you have an Elven bow. The problem is, I'm now level 23, and all the bandits and marauders have ebony or glass bows, and you can't seem to buy Elven anywhere either.

Any ideas on where to get an Elven Bow this far along in the game?

I don't believe there is a guaranteed way to find one in a specific spot. It is possible for venders to sell them. It is also possible for enemy archers to still carry them, although as you have found at level 23, not often.

Checking the wiki for this quest doesn't really help: http://www.uesp.net/wiki/Oblivion:Marksman_Training

Good hunting!

For an elven bow try the Archer Paradox in Bravil. Fingers crossed that one is there.

I ended up finding one for sale in Anvil the 3rd time through. I thought it would be easy since I must've sold 20 of them to varius merchants around Cyrodiil.

Never made much sense how the products that you sell don't stay in inventory. It did in Morrowind, I think?

Why would it not make sense that a vendor sells things to all the other characters in the world? What doesn't make sense is the way that the vendor's inventory depends for its item levels on only one character (the player).

Try undead archer skeletons. Skeletons and most undead usually have lower end weapons.

Problem is that elven bows fall below the levelled list for levelled bandits at very high levels. However at those high levels the shops carry the equipment but you have to check multiple as you say.

Merchant inventory stayed in Morrowind, Upside was that you could get back things you sold by a mistake unless the shopkeeper equipped it as he did if the item was better than something he carried.
Had one major downside except from being unrealistic, inventory was static if you had shopped at him once he would never get new items except consumables; potions, ingredients, arrows and repair equipment. Here fallout 3 and is pretty similar and much better.