As for what I meant, I found 50% to be the "fairest" value to use since I decided I would prefer keeping price negotiation in the back ground rather than have my players slow the game down with doing it to get the most profit.
The fact that it slows the game down is what keeps my players from doing it. They, like me, would rather spend our time at the table adventuring.
20% would encourage players to want to barter/negotiate for better prices/profits. IF they have any sense of numbers. For example, when they go clear out that evil hidden temple defended by 25 clerics and fighters wearing Full plate mail and heavy steel shields. If they realize the value (1,000 GP each for the plate, and 25 GP for the shields in the game I use/run) that is 25,000 GP in Plate and 500 GP in shields. So if they have any brains they will realize 20% of that sucks, and 50% of that is much better, and 80 to 100% of that would be even better.
By that logic, why didn't they spend time trying to get 100% or more of the value in previous editions? I'll answer from my experience: Because those were the rules. And 50% has become the accepted norm over a long period of time. That's seems to be the crux of why 20% seems unfair. Purely metagame reasons IMO.
So I tell my players I give them 50% with no time spent role playing the negotiations, setting up a store, etc... Most of the time they accept the 50% just to allow the game to move on. If I offered 20% they will be far more likely to want to role play getting better prices.
Not IME. Just like I told my players 50% in the past, I've told them 20% now and they have no desire to spend any game time haggling for a better price any more than they did in the past. Both are artificial numbers. Both make people ask the question "If I have to pay full, why can't I sell for full" but in the end adventuring is commonly more enjoyable to players than haggling.
Most games I have run usually has at least one person who understood economics/retail well enough to do some smart things to maximize their return.
Retail? Give me a break! That comment alone smacks of the MagicMart complaint that cropped up since the inception of 3E. 4E's default setting is PoL. Travelling merchants brave the wilds to sell their wares. Buyers are hard to find because only Heroes have the money and they are a rare breed. The "shinier" the stuff a merchant carries, the bigger a target. There is no real great correlary to the real world, except the fences that deal in the dangerous world of the modern day criminal. And fences in the real world don't pay 50%, in fact 20% may be a generous average.
So to try and avoid all this time role playing "Debits and Deficits" I just assume they do bargain and give them what would be the "average" with such an assumption.
They've played a game of chicken with you then and you've caved. Why would any smart player want to play "Debits and Defecits" instead of adventuring? And why would a PoL economy work like "Debits and Deficits?" Being a travelling merchant band in 4E could be a campaign all in its own.
Realistically, once you figure out a few realities of the "business" you will get closer to 100% of retail much more often than they would get as low as 50%, let alone 20%.
Yep, just find the neighborhood MagicMart. There's one on every corner!
So by just going with 50% your giving much closer to what "reality" will give them without role playing it. Hence why I worded things the way I did.
Modern safe realty. Walmart and mega-malls reality. Not a dangerous PoL world where monsters are everywhere and any MagicMart would be quickly looted by the nearest dragon to stock his hoard. "All these great magic items in one place? How did a Great Red Wyrm such as myself ever grow his hoard without MagicMart?!"
Now if you have a bunch of players who just don't care and don't grok the numbers game, then you can get away with 20%. Still, I feel guilty doing that, because I am in essence counting on them being "stupid", or to put it nicley, not knowing better.
"Stupid" = "Doesn't agree with Treebore?" Call me Stupid. Vyvyan Stupid Basterd at your service.
Plus when deciding how much their treasure is, I take the value of such equipment into account, so it isn't like they would get more. In fact I like it when I give them only 300 GP in coin, since they will get 12,500 GP from the plate mail being sold.
Then you haven't really changed anything, except to make it easier to decide to seel an item than to find a use for it. Exactly what I came to hate in 3E.
Which also makes much more sense to me. Evil Temples, Castles and other fortifications would have most of an NPC's wealth sunk into these structures. Either in beautifying them, equipping the henchmen with the best possible, buying procuring suitable monsters, etc... is where all the wealth will be. Comparatively very little will be in loose coin. IT will be in art, gold utensils, gold candelabra's, jewelry, magic items, armor, weapons, fine clothing, fine bedding, fine furniture, not coinage. Plus, the bigger the item is, the harder it is for someone to come in and steal. Especially a well guarded/patrolled location.
"Art, gold utensils, gold candelabra's, jewelry, fine clothing, fine bedding, fine furniture" = All sellable at full value. Because their value is only, well that they are valuable.
"Armor, weapons" = Sellable at 20% if allowed by the DM. (Which I do, because I agree that it should be sellable. The rules give the option at the DM discretion.)
You don't ever have to give out coinage if you don't desire.