I'm very interested in seeing what EU players would think about introducing league fees into ETF2L - maybe a poll would be good? I agree with Lupus here in that it will insentivise better competition and make EU a stronger region.
League fees need to be used in a way that they benefit a regular player. Some of the money could go to top level talent, But as Gazy has said, it wouldn't be very popular to just give money to high level talent + sandbaggers and keep the league as it is.
I believe that using league fees to create new services (Building tools like https://ozfstats.com, updating API, etc) or to create events (ETF2L Pugs/LANs/Cups etc) would be the way to implement league fees positively. Then you would also be able to boost winnings of high level talent.
There is of course some negatives to implementing league fees (sandbagging first comes to mind), but I think that if league fees are used positively they could improve the scene in EU and create a better comp TF2 experience.