  From my perspective, here are our 3 options: 1. Least Desirable : Joint purchase of your land/house, we purchase the next with a line of credit a. I would be on the deed to your house/mortgage b. Don’t know whether we would immediately be able to open a line of credit. Probably not until additional equity is built up. c. So there may be a long delay as you mentioned before being able to make our next move.
2. Next Least Desirable : You purchase your land/house, we purchase investment land/house same time a. You would have to come up with $20K ($10K for each purchase) b. Your credit would have to allow you to qualify for 1 mortgage by yourself and 1 with me as a co-signer c. You would have to service 1 and 1/2 mortgages, although I would also d. Construction time would have to be divided among the projects, extending the timeframe for selling the investment property 3. Most Desirable : You delay purchasing your land/home, we first purchase investment land/house a.
You only have one mortgage (1/2 really), which would cover the land, construction materials and labor costs (including yours) b. We would come out of our pockets for the principle/interest payments c. When we sell the property, we could take our original $20K investment out of the proceeds as well as principle/interest payments d. You would have the money back to do your own deal and we would have mad cash for the down payment on our next deal and also its principle/interest payments e. We would be in 100% profit mode 
