The best way to estimate house flipping expenses is to begin with a good checklist of expense categories. Start with my sample budget categories, found in Appendix C.
Next, ask subcontractors and suppliers for firm quotes on as many items as possible. For the remainder, use software, experts, or the Internet to calculate probable expenses. Bear in mind that most quotes are good for only thirty days. If there is a significant delay between obtaining the quote and beginning the work, you will need to request an updated quote.