First off, Paragon level is account wide.
Second, EACH Character get's their own set of points. As stated by an above poster, if you have a 199th PLVL Toon, all of your characters and even new ones you make will have 199 points to dash into their own Paragon stats.
Paragon DOES have a limit, and that's the stats themselves which seem to Cap at 50. Currently there are 4 Stats that we know of, Core, Utility, Attack and Defense. That's 200 points right there, so 2 PLVL 100s would be the max you'd achieve any way in terms of "upping one's stats" across any toon. Any more than that and the PLVL is only effecting the base stats of the PLVLed toon. We will see if they add more Paragon Stats in future.
Lastly, you can respec any character's Paragon Stats.
SO this means that no, you're not being forced into playing only one character. In fact it makes people level new ones faster, probably, encouraging more and more casuals especially to make an play through new characters.
This means the addition (one of anyway) of true customization which did not exist before hand. In D2 you could spec your Stat Points at 5 per level and each stat meant something for EVERY class. D3 RUINED this with having each class only get what they really need from their base stat while Vita remains a common pool stat. Paragon Stat leveling is almost like the return of the old stat points, letting you, the player, control how your character grows and plays; almost like the old days.
Lastly the economy will adjust accordingly with the new Loot system.
At first DEMAND WILL DROP
which means things will get stupidly cheap.
For one, End game is reset and one's currently owned 1.5k DPS Skorn will soon be worth squat.
To make it even worse, until people start hitting a gear level peak, selling any upgrades you get while venturing to 70 will be worthless because the game will be giving EVERYONE upgrades in a timely manner through smart drops.
Eventually, as more and more people peak however, the AH will once again be flooded with gear, and amazing gear at that since the Loot 2.0 system will try to give you gear within your toon's range of level and gear level. However, there will be a limit in the RNG for the items you receive so most of what you get after you reach that point you can flood the AH with; making it easier to lower levels to get HUGE upgrades rather than smaller ones.
At this point, the AH will again, be prime. But not required. It will simply add "Easy Mode" until those toons hit their peaks as well.
I have a feeling that after about a year, the AH will be used for not much more than it is now, but under easier terms. Mainly a Crafting Supply store and "Bobs Easy Twink for Leveling" equipment outlets to power level newer toons. The End Game will see a drastic drop in it's use and you're finds and use of the Mystic will drive your upgrades from then on.
Also, demand for all sorts of gear will suddenly not be so rigid to requiring you to only get gear with your Base Stats on it and let you be flexible as to what stats you may want to compliment your Paragon spec.
if this happens, than most gear should see an evened out level of Demand because more of the gear may be relevant to players choices instead of being forced to be STR and only STR on classes like the Barb.
As demand over all drops, the prices should shallow out too.
Over all, you'll see far less reliance on the AH to progress and only the severely impatient will use it. Like myself. Lol
I'm no credit card warrior, but if I have the gold, I'll spend it.
Why else would you be allowed to accumulate so much? To wipe one's !@# with?
There are only two things you should be spending gold In-game with in my opinion. Repairs and crafting. You'll obviously have very little reason to spend the gold on Item Venders. They are going to have nothing compared to what you'll see drop with Loot 2.0 and the Mystic further sinks this with the option to customize your item's stats similar to Charsi's old imbuing.
Edited by Einharjar#1817 on 8/24/2013 8:32 AM PDT