you can without the speech perks ( accounting for 100 speech skill) easily get the true value. one easy to obtain item with 20% better prices ( also known as fortify barter) is the mask of clavicus vile ( a deadric artifact, and very VERY easy to get) or thieves guild helmets (10% for nooby one and 15% for the better set i think), you can also get Cicero chest piece which is another 20%, the necklace of zenithar (10%) there's also another necklace of some deity with 10% that i found my first character ever and you can sometimes find regular necklaces with fortify barter up to 20% on them in general stores. so with all the best items above you can get 60%+50% from 100 speech, that gets you 110%, i'm not sure if you can actually get more then the true value for items but you could always try.( and i'm fairly sure i didn't list all " better prices " equipment int eh game). Now say you can get all the equipment listed above or for RP reasons choose not to, then there are fortify barter potions, which would be "random of haggling" and the highest I've seen was either 30 or 40% in game. Then there's the fact that many skills can be used to make large amounts of cash such as the normal Enchanting, or you can use Alchemy (easiest i think) or Blacksmith ( after the first 60 levels it starts paying off itself i think). and for those shadey characters you can always pickpocket everyone in Riften and if you get caught and your in the Thieves Guild then you only have to pay half of what your bounty would normally be. And guys if your having trouble with money try doing a bunch of petty quests or some factions Quest line. Faction Quest lines are always very rewarding.