The airline industry is not the only industry where "paying to put yourself ahead" occours. I put myself through university and came out penniless, with no promise of a job, even though I have a degree. I had to pay for numerous additional courses out of my own pocket to put me ahead of other people and in the end it landed me a decent, but very boring job.
For the record I have also sponsored my own flying, probably 30,000 pounds worth (plus lost earnings), and tomorrow I have my CPL check ride, so fingers crossed by tomorrow evening I'll have a CPL ME IR. This isn't just a whim either, I am making a serious effort to enter the commercial world, which is why within the next month I am taking my Instrument instructors, flight instructors and multi engine instructors tickets (all paid for myself).
I have considered doing the Eagle Jet 500hr turbine time, and know a bloke who is doing it. If by doing this I can further my aviation career and put myself ahead of the rest of the competition then so be it. I am 34, didn't go to OAT, paid for every hour myself while holding down a full time job, and even after this I appreciate that the aviation world doesn't owe me a living.
My advice to the thread originator is, if you can do these 500 hrs, then do it, but be careful with regards to parting with your money up front.
It is a sad state of affairs that a prospective pilot has to pay for 'experience' but it is a fact of industry in general. Training costs are higher in aviation, but also the rewards are much higher.
EA