Among their membership they’ll have people that will “sign on the loan” to bring the experience to the table (at a cost), and they might even have other more experienced investors that you can partner with (and give them some of your profit).  

What did it cost?

Once you begin to generate leads that fit their recent purchases/want to buy, run the numbers based on the ARV after repair value for after when they develop/fix n flip and subtract cost of build/repair, your assignment fee, and the original cost of the contract.

If you roll into town and you see a Marriot or a Motel 6, it's pretty obvious to you which one will (probably) cost more and which one will (probably) be a lot nicer.

I estimate the cost to be about $200,000 based on no hard data but the DSLD house that I bought cost $270,000. 

It is a nice amenity that doesn't cost much.  

Here's a breakdown:Project Details:Property Cost: $50KRenovation Costs: $30KResale Price: $100KProfit: $20K ($100K – $50K – $30K)For instance, if your regular income is $50K, and you add the $20K from the house flipping, your total income becomes $70K.

I added a 5% charge to vrbo to offset the extra cost  

My question is, are there any other potential causes for this sewage backup, and anything else I should be thinking about that could make it much more costly than $1,000 or so to remediate?

Well worth the cost.