So, I worked out the numbers over in
this post to smooth out the wealth curve when accounting for getting occasional tier N+1 hoards while still at tier N. Once you examine how experience is granted by difficulty level, and how that translates to the number of hoards expected per tier, it's fairly easy.
It does, however, significantly shift the expected wealth of characters by level.
In addition, I wanted to look at how it compared to the Pathfinder curve from post #21. I had to kind of guesstimate the numbers in the image, and I extrapolated the numbers after level 16 based on the rate of increase in the previous few levels (4 levels in a row with a +30% increase over the previous one). And I ended up with this:
[sblock=Pathfinder]
https://i.*****.com/pIoVDYF.png
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Up to level 13, they basically match up. From level 14 on, though, the 5E results go
much higher than the Pathfinder results.
In any case, before this bit of rethinking, I had considered using the wealth at end of tier as a gauge for how much an item might cost. That is, how much of the wealth that you expect to earn over the levels 5 to 10 would you feel is appropriate to spend on your +1 weapon? Armor? And various other magic items. Rather than a fraction of the wealth you have at the level you expect to be able to buy it, have it a fraction of the amount of wealth you'll have available to use during the period you're likely to use the item. Once you get to level 11, and start looking for a +2 sword, you've used up the 'value' of keeping the +1 sword.
This was easier to consider when the expected wealth at level 10 was 20k gp. Now that it's at 70k gp, things aren't quite so reasonable.
And, giving it more detailed thought, I realized that there are mistaken assumptions in the idea that players will get loot hoards from tiers higher than their own. Namely, that the hoards have to be from single mobs, or else the CR falls back into the current tier. My experience is somewhat limited, but I rarely find myself dealing with fights of just one enemy. Those tend to be very do-or-die encounters, where you end up with quick deaths on one side or the other, depending on whether the players can counter the big problem that the enemy brings into the fight.
So, I did a re-analysis of the problem, and came to a different set of conclusions. Post
here.
Copies of the important graphs:
[sblock=Graphs]
https://i.*****.com/93xtUD5.png
https://i.*****.com/Uxn9Tz8.png
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This puts things closer to the original assumptions, but with a chance of one over-tier encounter on the last level of tiers 2 and 3. Basically, you get a boost in wealth (and possibly things to spend it on) as you near the end of each of the middle tiers, either to deal with the campaign-ending fight, or to get a little running start towards moving to the next tier of play.
As such, it's more reasonable to consider pricing based on the idea I was working on: Price relative to total wealth gained
on this tier, but not counting the last level of the tier (for tiers 2 and 3).
Prices for tier 1 items should be relative to 640 gp.
Prices for tier 2 items should be relative to 18,000 gp.
Prices for tier 3 items should be relative to 100,000 gp.
Prices for tier 4 items should be relative to 750,000 gp.
Since the wealth listed per tier includes the run-up level (ie: level 10 is part of tier 3, level 16 is part of tier 4), you don't have to worry about accounting for that when taking a fraction of a tier.
Note: Tier 2 is actually closer to 17,000, but 18,000 works better for getting fractions of a tier.
So, for example, what fraction of a tier of leveling is having a +1 longsword worth? 10%? 20%? 33%? You do need the armor to go with it, too, and possibly a third item, and you do want to be able to acquire it before it's effectively obsolete as you move to the next tier.
If you make it 1/6, and maybe get an armor to go with it, you might get one item at level 5, and one item at level 6, and have the use of them for the next 4 levels. That doesn't seem unreasonable. And if you're presented with another magic item option, you might think about whether it's worth delaying picking up the sword by ½ a level, or the armor by a full level, etc. If that's what it feels like it's 'worth', then you have an idea of how to price it relative to the other items.
So that would be my approach: What fraction of this tier's time is that item worth?
Note: This is separate from the question of what the minimum level to acquire an item should be. If you don't want the players having a greatsword+1 til level 9, just don't have them available in the shops. If you want sovereign glue to cost 100 gp, but not be available to players below level 17, it's likewise a perfectly reasonable combination.