More than anything, this is a not to myself, I often find myself bugged down by the details of a transaction, especially the bills and the pennies. This is not to say that being detail oriented is not important, but a major risk is the inability to act.
When you are focused how you can get a deal at the absolute lowest price possible, you find out that you lose out on more deals, and the fewer deals you do the less you make ultimately. The most important thing is to start by working out the numbers on your own and remember that time is the most important factor in a property investing.
Sometimes you need to spend a little more to secure a deal; so long as the numbers are right, you are making a profit and the deal reasonably cash flows. In the same vein, do not be afraid to walk away from deals that are unprofitable, do your research and don’t rely on the estimates that the seller provides (it is usually understated).
A good approach is to think more strategically about how much it will cost you overall, and how much you can make from it, then crunch the numbers and if it makes business sense just do it. Maybe you will make $10 less per month if you were able to squeeze the last drop from the seller, or maybe you lose the deal all together as a result of over analysis, what I like to call analysis-paralysisJ.
Long story short, don’t nickel and dime, think strategically and make informed decisions.