Paying to go to the assessment is to get rid the people who go into the aviation industry just for money (like you) and the really passionate people (like alot of the people on this forum).
At the end of the day if you want to become a pilot because of a passion you have then you'll get through it easily (depending on your preparation obviously). If you just want the job thinking you'll get lots of money then you'll fail: you'll either get kicked out at interview stage, drop out of training or leave the industry in a few years because of boredom.
Thats my 2 cents.