Expensive
Marly Lite.
Your post is interesting in that it reveals quite a lot. When considering the "twin only route", most make the same mistake. We fly XXXX number of hours now so the same number of hours in a twin will be expensive. Correct. but you miss the core point. A twin only route is a complete change it combines every aspect of the syllabus from when you walk in to when you graduate. You dont lift the old stuff and just put in the new aircraft - you have a complete reset and start again. It works if done like this and saves time and MONEY but requires simulators, part task trainers etc. Lots of others around the world have done the analysis. Some have taken the bold move and the results look good.
Now, at about this stage people ignore the increased speed to produce frontline pilots, the reduction in cost, the reduction of time in training and the reduction of the carbon foot print and say but but but, the Squirrel is cheaper! Well thats good then. You carry on as the rest of the world changes around you.
Oh, the other battle cry is normally, but that will cost so much to put in its not affordable. Well let industry sort that for you - it worked in 97 so it will work again. Lets face it, there is no going back now.
As to the person who is rapidly turning into "he who shall not be named on a pprune thread". Give him a break. All he is trying to do is find a way out of a puzzle with the resources he has. It might be odd or even strange, but at least he is doing something! The true way is the above but he cant do that now can he!