Help with understanding Cap Ex, Repair Costs, and Vacancy Rate

[Sean MIddleton]

I am in the analysis paralysis stage of learning before starting to invest in real estate. As I am running these numbers I feel like its a complete guessing game for the Cap Ex, Repair Cost, and Vacancy rate percentages. I have been running all of these at 10% each to ensure I don't get burned. However, this seems overly conservative and makes a huge difference in the over all ROI numbers. It seems really tough to find any deals that make sense running the number at 10% across the board for these. Does anyone have any set methods or systems in place for calculating these percentages? Any help would be much appreciated.