I am not a spokesman for these schemes, and a search here will reveal quite a lot of the information you want. I understand that the TR+ line training will cost around £18-25k from most of the companies involved. Some may hold out the carrot of a position with the host airline 'for suitable candidates', but I wouldn't bet the farm on that. If you decide to go this route, you are contracting for a type rating plus a number of hours' line training and nothing more.
Whether such training will give you an advantage in the job market isn't easy to say, but I can tell you that plenty of Pprune's wannabes have been employed in the last few months without such training. My gut feeling is that they are far less advantageous than they once were.
Scroggs