To get a sense of a typical DnD economy can be tricky, the following tables compiled by DM David can really help with this.
The following table shows the wealth a party will gain over their career, to be divided among the PCs. The hoard values come from calculated averages. The value of a hoard at a tier tends to be 10 times the value of the prior tier. This fits with D&D’s tradition of steep increases in treasure. All treasure values are in gold pieces.
|Level||Hoards at level||Encounters
|Hoard value||Gold at level||Cumulative gold at start|
|Wealth at end of career:||3,207,042|
This table shows the magic items each member of a party of 4 will gain when they
score the typical number of treasure hoards. To keep pace, parties with more than 4
PCs will need to gain magic items from other sources such as more hoards, fallen enemies,
or a magic item market.
Andy Pearlman presents an exhaustive analysis of the treasure tables in this post on Magic and the Math of 5E. He concludes that PCs will claim about 5 items over the course of their career rather than the 6 listed in my table. Also, his analysis shows that +3 and other legendary items start trickling into the PCs’ hands at level 11.
|Level||Consumable items||Permanent items|
|1||1 common||1st uncommon|
|5||1 common||2nd uncommon or a 1st rare|
|8||1 uncommon||1st rare or 2nd uncommon|
|11||1 rare||2nd rare or a 1st very rare|
|14||1 rare||1st very rare or a 2nd rare|
|16||1 very rare|
|17||1 very rare||1st legendary|
|18||1 very rare|
|19||1 very rare|