Companys get large discounts as opposed to people walking in off the street, so see if you can ask any favours with operators.
Also are you sure its not 24hrs in the sim?.. 12 as PIC an another 12 as SIC. If you havent flown in a multicrew aircraft, then being copilot is the hardest job as you will have your hair on fire running checklists etc.. so overall good experience.
FSI is expensive, but reallly good training, if you could find someone else who was interested in a rating and went in as a team, that might reduce the price a bit, but it is still painful. My last recurrent their was 21,300, (not a lear), hurts a bit doesn't it!