I'm pretty certain you don't pay the full 150K upfront, you most likely pay it in installments, just like when studying at a university (which is part of the cadetship), you also have the potential to get FEE-HELP from the government (I think they'll loan you around 100k). Based on past forums, I've read some people being accepted into the cadetship late 30s even, not quite sure 40s beyond