What you might want to do is have an agent help you find a lease/purchase home. This would essentially the same thing. You can structure the deal to be just like a mortgage. Now some questions that the agent will need to know is;
A) how much money you can afford to put down as an "option" payment. The option payment is traditionally non-refundable. What the option payment is for is to "buy time" since the home is for sale you are paying the owner to take the home off the market.
B) How much you can afford as a "Lease payment". Now a good agent will structure the deal to include a percentage of your lease payment to go against the purchase price just like a mortgage payment.
C) You will have to have an idea of how long it will be before you will be able to move ahead and purchase the home. The sellers will want a deadline even if it is two years that they can look forward to selling the home.
Now to find one that is less then 30,000 it will be more llke an investment property that needs some work.
Hope this helps,