In the DMG under magic and wonderous items, it seems there is no value or price per object. I look at the tables where they are listed and I look at the item description itself, and I don't see any prices anywhere. Are there any prices for these items? I want to know how much a Sun Sword is worth! Or a pair of Gauntlets of Ogre Power! Or perhaps these were left out on purpose?
The in-universe reason is that these items are essentially priceless. There is no market for magical equipment, so there is nothing to set the price by. The meta-game reason is that the "magic mart" was a percieved problem in 3E, compounded by 4E calculating expeted bonuses from magic items into its combat rating math, thereby requiring a certain amount of magic gear per level, which for many people ruined any feeling of magic items being special. 5E has gone to the opposite extreme, opting to not include prices for any individual magic items, giving only rough guidelines based on rarity.
Honestly, I don't think that the 4e problem is that it stopped magic items from feeling special (in terms of effect). I mean, the bonuses stopped feeling special (as they were worked into the math), but the abilities/features sure felt special! It was really nice to have an extra action you could use. The main problem is that the fact that the bonuses were baked into the math, that you needed items with higher bonuses to stay relevant, and that you couldn't have the higher level items available to lower level characters (or the math of the game would break), resulted in a treadmill of wealth acquisition that made no sense from an in-game economy standpoint.
I'm with you Cyber-Dave, I so prefer how 5th Edition is handling the method of wealth, t's the story that matters. I jumped up and down when I saw no prices for magic items. Still smiling about it.
So for example, what if I have a mage or somebody selling +1 weapons? Should I do 1,000 gold plus the weapon price?
Slit518 wrote:
Cyber-Dave wrote:
If you want more granula magic item values, using the 3.5e ones or the Pathfinder ones would largely work. Be careful on prices of +1 weapons and armour (I personally wouldn't hand them out in a world with a magic economy) and the bonus other items give may be quite significant in 5th ed whereas they weren't as significant (and so not as powerful) in 3e-era editions.
Slit518 wrote:
JohnLynch wrote:
Devils-Advocate wrote:
Slit518 wrote:
The price of a +1 weapon is your immortal soul and those of all your friends and family.
The price of a +2 weapon is the combined immortal souls of an entire city.
The price of a +3 weapon is the abolition of an entire race. Starting with yours.
Are you buying or selling? 
Slit518 wrote:
Look, the pricing in the DMG makes absolutely no sense when combined with the rest of the information. If you want to create a 'magic economy' you are pretty much on your own.
The only way p.135 makes any sense is for selling items immediately. Kind of like going to a pawn shop with a picasso.... there is only so much they can give you.
The default idea of the DMG seems to be that magic items are not gold driven, but plot driven. You don't 'buy' a +1 sword, you either find it, or you research the location and go after it. Same for selling... sure you can sell it to the farmer for 5 gp and a pig; or to the local noble for 300gp (maybe), but if you ask around, and travel a bit, you can meet with the Duke that really wants it, and will trade you a small keep and control of a hamlet for the sword. (You will have to clear out the keep first...of course)
If you want to make an economy out of it..... then you need to have some way of restricting access, getting your choice of uncommon items for only 100-500gp will be really powerful.
Carefully reading over the Rarity and Buying and Selling sections of magic items in the DMG revealed a few more reasons there aren't magic bazaars by default. Most of the techniques and secrets of crafting have been lost, so all but common magic items are often antiques and objects of lore. Scrolls and potions, when available for sale or trade (which might be for services than gold), are generally half the listed price as they are one use items, and even then generally only avaible in cities or other locales with lots of magic users.
Since the range for common magic items is 50-100 gp and the minimum character level is three, I'll assume that 1st level scrolls and potions cost 50 gp and require 2 days to make while 2nd level scrolls and potions cost 100 gp and require 4 days to make. Allowing PCs to make scrolls and potions for their own use takes their time and money, and while it allows them to have more expendable resources during active adventuring it also means that character isn't running a business that might make them money during said time. If they do decide to sell the scrolls and potions they make, then you can get a plot hook that gets them in trouble if the only lead the city has on a crime is the magic item the PCs made, especially if they don't make sure to know (or verify) the identity of the people they sell them to.
There is, of course, the fact that most people in the game world can't afford a magic item, or would rather spend it to raise a personal army, fortify their mansion, eat more exotic food, indulge in various vices, or other, easier to obtain resources, consumables, and services.