The Transfer List is a market. A buyer and a seller agree upon a price for a given player. If a buyer is lucky, then many sellers are competing for the same player -- higher demand, higher price. In this way, it is like any free market (cars, stocks, houses).
There are, however, many facets to the TL in BuzzerBeater (as with so much of the game). I am convinced some player types and skills are undervalued, others overvalued. (But you may value a automatic transmission, and I prefer a manual. You like centers that can rebound, I insist on all my players having a good jump shot.) Not everyone agrees, but I also think there is an ebb and flow to demand -- some parts of the season are a better time to shop than others -- everybody needs a superstar before the playoffs or relegation rounds.
The only way to figure out how far $200,000 will go is for you to go to the TL and see for yourself. I would fool with the search parameters -- begin with $200,000 as the bid. See what turns up. Then see how, say, age affects matters. Then try potential. Then salary. Different skill sets. Have fun: look for players 6'10" who are labeled "Shooting Guards". You will learn a lot quite quickly.
And if you are looking to buy, you will see how many different people play this game, and what they value. You will start to see what kind of player catches your eye -- don't rely on the judgment of others. Lots of dang fools bought Edsels and Hummers.