Under 1k players are those with skill sets that are very low (mostly atrocious). I think managers just price them really high as a novelty. Just fun to see a multi-atrocious skill set. Fan survey benefit would be this line...
I am familiar with the star players, and am not afraid that they will be transferred
Merchandising benefit would be that you drafted them (assuming you trained them also). Not to pop your bubble, the economic gain is very little and can be dwarfed by other economic boosts to the game like having a NT player play on your team or winning consistently. Winning streaks are another catalyst for increased attendance, etc...