For each line-item, you can get an idea of the material cost by visiting your local big box store, building supply shop, online retailer or talking to other investors. 

I have also sold a few houses to retail buyers with asbestos siding. 

These sound like retail, "I'm gonna get fat if you pay me these prices" pricing.

If you can master the concepts in that article you can analyze stuff pretty well with a 5-minute procedure instead of building massive spreadsheets that don't add a whole lot more value.

Then you split the 'excess profits'.Looking at your great work, you may want to go after some of the 'white elephants' in Atlanta AND/OR do new construction with retail values of $800k and up.White elephants would be like the house in the Highlands you did.

I currently work part time at a national home improvement retailer.

(seems to have the same estimates) the site gives you prices bought for cash bought properties and prices for retail.

Have you considered NNN retail?

I've already had a Realtor work out a retail value for this property, which we calculated to be $230K-$240K, once renovated.

Personally I am looking to get rehab experience in CA so I can get experience turning distressed properties into retail worthy properties without adding the learning overhead of rehabbing virtually.