I did: PPL, 800 hours private flying, FI, Para dropping, piston twin air taxi to 2000 hours, bizjet. Makes sense?
I was not asked to pay for my rating but did accept a bond, decreasing pro -rata over 2 years with a decent salary. If, however, you have little or no relevant experience and won't /can't put in the hard yards then you may see paying for a rating as an option. You might get lucky and land a RHS "job" with a private operator on some dodgy register with a 70 year old alcoholic captain who left his last airline before he was pushed. He'll tell you all about the good old days when the Captain was second only to God and all that CRM c***p hadn't been invented. He can't believe that these little jets have to be operated multi-crew and as you won't have any SOPs anyway, he'll continually show you how it should be done while you do the flight planning, serve the passengers and operate the radio (for little or no money).
And that's if you are lucky enough to find a position on the type that you have paid for. How you will kick yourself if a job comes up on one of the other 50 types that you could have gone for but only if you pay for the rating.....
But then you know this deep down, don't you? Just like the lemmings trying to get airline jobs straight out of kindergarten. If you have no respect for yourself then don't expect an employer to respect you and certainly don't come on the forums in a few months'/years' time looking for sympathy for your poor treatment.