I figure the ones over 50 or 60 years old have already had all the big ticket items replaced.

Focus on the big-ticket items and estimate costs.Financing: Whether it's private money, hard money loans, or a traditional lender, make sure your financing is lined up.

If, however, there are any gaps at all in any of the above items, even a gap so small a mouse can squeeze through, that tenant will exploit it and your life just became a 7th Level of Dante's Inferno.....:)

I then would have my tax cpa enter in or do it after discussing tax based items (depreciation- MACRS, reserves, year end accruals, reserves, etc.).

The Detailed Engineering Cost Estimate Approach is typically used for the purchase of used property.SURVEY OR LETTER APPROACHOnce a site inspection has been completed and all components of a property have been determined, your specialist will send a survey or letter to the contractors or subcontractors to request they provide the cost of each of the items.

This property needed an extreme amount of clean up and haul away of items left behind.

Go through each major line item and come to an agreement on what really needs to be done.

Plumbing, windows, driveway, etc - all big ticket items. 

-When a tenant moved out, the management company refunded their security deposit but failed to account for damage, such as holes in walls and outlets ripped off the walls, leaving me with repair bills and also tenants moving in without the repairs being done.Stuff like this that is consistent and when I ask questions they are defensive, when I ask for more quotes for high ticket items they are defensive. 

The loan does need to be secured by the property being improved if we are talking about a personal residence and personal itemized deductions on Schedule A.