All the wholesalers that consistently make significant money in this biz I can assure you are able to within 15 minutes make offer on property based on comps and repairs to get in A-1 shape. There however are fine lines that you do need to be aware of.

First off, if you can't get in side the house you have to assume most everything has to be replaced and/or upgraded. Secondly, you do need to leave yourself some escape/weasel/contingency clauses in case for example there are extraordinary repairs needed if your offer is accepted that you couldn't forsee. For example if when you get in the house and go to the base and find mold growing on every wall and will be staring a $20K mold remediation bill.

Its an art in wholesaling and you just have to be making LOTS of offers to get the ones accepted versus the majority that get declined. I use to work hours and hours in detail on my offers with detailed repair lists only to get my offer shot down in a matter of seconds being $10K off base. It just didn't maximize the best use of my time.

In summing it up with wholesaling, you have to be so far inside the "safe" margin on your offers that even if Murphy shows up(Murphy's Law), that you can still profit from the deal. And lastly, contingency clauses you should use for your protection on the unforeseen so you're not the unforgiven.

Thanks
Scott