by Balidil Anla'shok
Charisma and Faction
As far as vendor prices are concerned, factions can
be broken up into three categories. Dubious or worse, apprehensive,
and indifferent or better. If your faction with the merchant is
dubious or worse, of course, the merchant simply won't sell to you
(I have something here that %Rs use..let me see...it's the EXIT,
now get LOST!). If you're
at apprehensive, the merchant will sell to you, but is going to
charge you an arm and a leg unless you can get your charisma WAY
up there. Lastly, any faction indifferent or better will get
exactly the same prices for the same charisma. It doesn't matter if
you're ally or sneaking and indifferent.
There are several crucial charisma numbers to shoot for. Key to this is that, whether your faction is apprehensive or indifferent or better, there's a stretch from 61 or 62 to 76 or 77 (I haven't been able to get a gear combination that gives any of my characters either 61 or 76 charisma yet, unfortunately) that gives exactly the same prices. So, if you can get your charisma up to 62, don't bother getting any more charisma boosters until you can get enough to get you to 76. However, when you do get to 76, the prices will suddenly drop by about 6%, instead of the 0.5% you get for most individual points of charisma.
Better known is the "magic number" of charisma, 104. This is the point at which indifferent or better merchants will give you the best price they're ever going to give you. This price seems to be based on 1.05 times a "actual value" that you will never see used, but is only directly known by the server. For instance, many gem and metal prices are clearly based on this. And, if you notice the prices at which the vendor will buy such things back from you, although it looks like a very irregular number, for instance 95pp 2gp 3sp 8cp for a bar of platinum or a sapphire, that just happens to be 100pp divided by 1.05.
The last and highest number to shoot for is 132. This is the charisma at which you can normally get the cheapest prices even with apprehensive faction.
The Pricing Roller Coaster
When many players have been buying from or selling to
a merchant, he seems to get it into his head that "Hey, I'm so
popular, I can charge better prices now!". Unfortunately, "better" in
this context means "better for the vendor". I'm still carrying out
research on this issue, but merchants that will normally give best
prices at 104 charisma and indifferent faction can go at least as
high as needing 134 charisma to get best prices, even with ally
faction. It seems that, with less charisma than that needed for
best prices, a set amount is added to the price you would normally
get, i.e. whether your charisma is 120 or 50, a vendor might add
3sp to the price you would pay from a vendor who hasn't been getting
so much action. The actual amount can vary widely.
This is particularly noticeable on merchants in very busy areas, for instance vendors located in or right at the entrance to newbie areas, or those in banks. In these cases, it's almost impossible to distinguish a "greedy" merchant from a merely "opportunistic" merchant.
Stacking and Prices
When buying or selling items by the stack, the cost can
be a bit more precise than the single item cost times 20. This can go
either way, making it more or less efficient to buy or sell by the
stack. One classic example is water, and other common items that are
bought for 1sp. Since the real cost is 1sp and 1/2cp, even though the
per item cost is rounded off to 1sp, when you buy a whole stack at
once you pay 2gp 1sp, a whole 1sp more than buying them one by one.
On the other hand, with my Iksar's rather low charisma, he gets
shuriken for 1sp 3cp each, but if he buys a stack, he only pays
2gp 5sp 9cp, and saves a whole copper!
In general, to the best of my knowledge, this can never make more of a difference than 1sp per stack. So I usually don't bother with it myself, and just buy my water etc. by the stack.