I suppose scarcity as a theme of being low level is reasonable, but depending on the person it might be a detriment to their experience due to the irl sink of time required to accrue the money required for items sold by either NPC merchants or just PC merchants in general.
The way I'm kind of looking at this is from a game-play and community perspective. There are a number of players who are reliant on the crafting system to sell things to players for money they need, and there are just people who sell stuff that they ninjalooted to people for money they need too, but there are some people out there who do neither of these things (either because lack of familiarity about what sells, or lack of patience and time) and they're just reliant on npc merchants to get the gold that they need for items and armor required for their build (most often new players and low levels), which is often sold by player merchants who often have set prices for their items and wares that is above and beyond what a NPC merchant might sell it for if someone simply decided to vendor it to them.
When you're a low level, you're really starved on gear and the necessities needed to make your build or time in game a successful one, so you need to spend time making gold by doing one of two things: Running and doing dungeons and adventures with other players, or running and doing the delivery NPC quests. Someone could add that a lot of players make money by selling items to crafters, but there are sometimes periods of time where players are unable to accomplish this, so we are defaulted to the two constants.
The most popular way of making money is method number one which rounds out to the the reliance on NPC merchants to make money, however with the cap that exists on Petre compared to other NPC merchants, most of the people reliant on him make only a pittance when they sell things to him especially if they have to split the sharings with other players at the end of the day which results in the need to grind more and do more dungeons in order to get the things they want or need to be successful, which is also a considerable time sink. Some people have irl obligations and jobs to attend to, so they don't always have the opportunity to do these things.
You can make better money by running deliveries, but continuously doing these over and over is also a big time-sink and gets really boring for people doing it over and over, when they could be doing the alternative of RPing with others and having fun doing dungeons, but make less money that way.
This is a long ramble about my thoughts (which I think kind of over-complicated the core idea, but I kinda wanted to make my reasoning more clear) but I genuinely think that if the cap was raised by even a small amount, like 100 gold, it might at least make a difference for the low level experience or new player experience in general, for both new players and old players alike. Not to mention it will benefit people who sell things to players in that sphere as well, encouraging more positive player-to-player interactions in that regard.
