How do you arrange payments (partial upfront, with balance at completion)?

If you call the store manager of any big box store and tell him your business is rehabbing apartments and you would like to start a purchase arrangement with his store, you can expect 10-15% discounts off of the shelf price. 

Not only do you need a new contractor but may need someone to step into their PM shoes.Many owners have made these type casual arrangements work but there are inherent risks.A PM on the other hand is in the business of providing a service and also, I believe, has fiduciary duty to you.

You will be sacrificing getting on with your real estate experience and holdings, but would be doing a good thing for aging parents and will have a good asset paid down and ready when you are both ready for other living arrangements.  

Mario, while it can be difficult to find someone interested in the kind of arrangement you describe, you also may not be legally entitled to any rent for a residential unit that does not have its own certificate of occupancy.  

That contract arrangement would be void.  

This has been their arrangement for almost twenty years (the tenant has lived in three of the landlord's properties, all located in California) and from inception there was never a written agreement for this arrangement.Now the landlord wants to have them sign a lease and write them checks for the work that is being performed, which apparently is to be cashed and returned right back to the landlord as the rent payment.

I arranged a mover for them and the day I provided them with the security deposit (it was actually given directly to their new landlord) they were gone and the problem was solved in less than 4 days.

Your agent can also make arrangements to show the property and write your offer.  

Were you in contact with other real estate investors beforehand and worked out arrangements to workout a double close?