Short answer: whatever you want.
Long answer: There is intentionally no weath by level table. Except for armor, there is nothing PCs can buy that improve themselves (the "balance" aspect you mentioned). I've used PCs at higher level with only starting equipment, and they were fine. If you want a guildine for the armor, I would suggest they reach Splint at about level 4, Breatplate at level 6, Half-Plate at level 8, and Plate at level 10. YMMV.
How quickly do you want your PCs to get better armour, silvered weapons and stashes of healing potions?
Right now the characters here are going through the Lost Mine adventure and I am boosting the treasure amounts based on my intuition (since I know the characters will be going through the money quickly enough for a good while). If anything, they will still be 'hungry' for more and have just enough to keep things interesing. 
Perhaps going with your gut feeling on the amount to include while observing what your players are spending those shiny coins on or working towards on an adventure by adventure basis?
If it helps, I think someone calculated the Lost Mines of Phandelver to work out to 1200 gp each for a 4-PC party and that spans levels 1 to 5 and assumes all the gold is found/earned. That may give you an idea of how much the designers are thinking, though I don't think it matters much. You can't buy magic items (well, directly) so there is no real concern about balance there. If I don't see anything to spend money on in future supplements, I'm just going to make it very abstract, sort of an easy come, easy go vibe and never track another coin again. I might even make a Resource roll mechanic to determine whether the PCs can use their money to do something for any given uncertain outcome.
I would be conservative personally so low level characters don't start buying castles after a few adventures.
By the way, I have a feeling the DMG will have a lot more to say about in-game wealth, but we shall see.
There may very well be more concrete guidelines when we get the DMG
Who knows? Perhaps the next update to the Basic DM pdf (0.2) will have something on this? 
It would be quite lovely if it did!
I have a "feeling" that the next Basic rules update should coincide with the release of the Monster Manual core book near the end of the month. 
It's kind of an art really. I agree with Atheosis to be conservative, but if you're too stingy PCs get frustrated. I tend to be a bit more stingy with some magical items, not wanting to unbalance the game. With money, you can always limit a PCs access to what he can purchase. It's hard to limit that +5 weapon after you wrote it into the adventure during a manic phase without being a reall jerk. Start small, after a while you will get the feel of how much is too much and how much is just right.
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