Price isnt the issue with texturing with the market.
The time investment is the issue, especially with the top tier or older texturers.

consider how long it would take to make a set of consistent quality, for a 50k head texture.
No amount of fictional currency is going to convince me to spend a full week of free time making a set.
forget that people actually have social lives, responsibilities and sometimes want to do things other than texturing.

convert TC to real world money, 5 hours a day, 5 days, thats 25 hours, how much should one charge per hour? lets keep it away from real world money and keep it to hobby level. google tells me minimum wage in the US is 7.25$, so lets say, for toribash texturing, i charge 4$ an hour, should i then charge 100$ for a texture set?

Ofcourse not, that would be ridiculous.
but thats the point, for the top tier, price isnt the issue, its a hobby.
Time is.

if there were more incentive for texturers to spend their time around here, sure, youd see more high tier texturers making more sets and full sets might actually become a viable profit earner.
look at games like dota 2, item sets go into the market and they get sold to thousands, earning artists tangible money.
here, its a once off deal, you sell a set once, you make money once.

Time vs Price

heads take less time than full sets. so theyr the easier earner.

There are some people that have made sets and made just as much more than selling heads like PLN and 13chillz it just depends sometimes, some players and i would pay up to 500k or more on a pln set if i had requested one from him or something