You have a skewed sense of resources, of which time and money are subsets. If something is FREE it means you spent absolutely no resources on it. The closest you can get to free is if some random stranger you've never met before gave you something. The cost in either money or time for extra Retrofit ships is just too high.
As i said i don't put a price on my free time, it'd hardly be free then would it. i'm talking money, cold hard cash, green backs, dollar bills, pounds, cents, lira, rupiah, pieces of eight. do you have to put down a single one of them to get that ship?