Worked on my own list of magic item prices based on chart placement and percentage change of acquiring.
You can find it here.
I don't agree that that constitutes "trivialization" of the encounter. It makes it a regular encounter where good planning and good tactics and good use of terrain result in victory, possibly even a victory at little cost to the PCs. The original claim was that you can't use hobgoblins at high levels because AoE spells trivialize the encounters, and that claim has been thoroughly debunked by subsequent discussion including your recent post
Are we now on compatible pages, if not identical pages?
If the kobolds are really just trying to get the players to chase them into a dragon's lair so they can turn the tables, then the real dramatic question isn't "will the kobolds stop the PCs from entering the caves?" but "will the cunning kobolds draw the PCs into a trap?" In this case you'd want to play out the encounter past the point where it appears to have been trivialized.
News flash! "Internet argument resolved amicably and productively! More at eleven!" This is why I like Enworld.
I will honor my signature and say, i believe this thread has been exhausted. The rest of it is some kind of off-topic about monsters and even that is over...
The original question got an adequate and valid answer on page 1.
FWIW, I'm *still*baffled at how a PC could say "Well, all this gold and silver is useless, without magic items for sale. I guess we throw all the coins down a well." I mean, there's been a bit of an answer, but not from anyone who actually says that in character, nor from a DM whose players are saying that.
Short version: Gold is useless unless its making me moar powarfulz!!! 11!What else is there to do with gold? There is no other equipment progression beyond plate mail, most consumables besides healing potions and also upkeep is glossed over (and when not they are trivial). The often mentioned carousing pretty much is equal to throwing coins down the well as it serves no purpose. There are some big ticket items in the rules (hastily added when the designers realized that their reward balance is broken without magic items in my opinion) like strongholds and ships but, like bribes, they are extremely situational and there is absolutely no guidelines in the books about how to handle them in game neither for the DM or player making them more like vanity items than a actually useful things.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.