Based on the comps, I leased less than the market rent and planning to lease per market after expiration of the current lease, so I may be able to make additional 100-150$ a month.During the weekend, I get a chance to meet tenant and during the conversation, we both expressed our interest in converting this lease to 'lease to own' option as the tenant is having not so good credit history and like to buy this property after he is able to repair his credit.I have neither done 'Lease to Own' transaction nor do have knowledge in it.

What I do to find if the owner may be willing to sell via seller financing, is I check the sales history of the property and see if their selling price is close to what they originally purchased the property for (possibly ten to twenty thousand dollar difference at most).

It sounds like you have some credit history already being built with your car.

Do I need to move to an inexpensive rental property in the meantime so I can start establishing rental history on the condo?  

Look at history.  

During the worst depression in history, people were buying garments the raw materials for which cost between 6 months and year's worth of average wages.  

I'd submit a letter explaining why you want to purchase the home, how it fits for your family, rental history, work/personal references, information from the lender explaining the time frames for you to obtain your own financing.  

Alain, I'd love to connect at some point regardless of your history of rather questionable educational institutions hahah.Glad to see I'm not the only one starting from the bottom.

I was told by my bank that they would count 70% once I had two years of rental history under my belt.  

Have rented for Foreign Nationals, who recently moved into the country and didn't have credit history to get a mortgage.