See the chart from Fair Isaac Company (FICO) below: FICO Score Pct of Population Default Probability 800 or more 13.00% 1.00% 750-799 27.00% 1.00% 700-749 18.00% 4.40% 650-699 15.00% 8.90% 600-649 12.00% 15.80% 550-599 8.00% 22.50% 500-549 5.00% 28.40% Less than 499 2.00% 41.00% Source: Fair Isaac CompanyAccording to this chart, investors should use corresponding vacancy+tenant-nonperformance factors of approximately 5% for Class A rentals, 10% for Class B and 20% for Class C.To address Class C payment challenges, many industry "experts" are now selling programs to newbie investors about how Section 8 tenants are the cure.

The last time we failed a section 8 inspection was approximately 30 properties ago and then passed our second inspection on that failed one with flying colors a few weeks later.

Basing estimates of rents and expenses based on my existing knowledge of local markets.

This not only lets your get a discount when these suppliers compete against each other, but if you have detailed plans from an architect or a spec for the build out - they can also estimate all the materials needed for you.

I can’t get my budget in order because this one builder won’t give me an estimate until I’m ready to apply for permits.

@Rahul Sivaswamy if you use the BP Rental Calculator, it defaults to 5% Vacancy, 10% PM, 10% Maintenance, etc.These are all pretty good estimates, except the Vacancy factor of 5%.

(vii) would seem to indicate that you'd be acting as an unlicensed broker.(1) "Broker":(A) means a person who, in exchange for a commission or other valuable consideration or with the expectation of receiving a commission or other valuable consideration, performs for another person one of the following acts:(i) sells, exchanges, purchases, or leases real estate;(ii) offers to sell, exchange, purchase, or lease real estate;(iii) negotiates or attempts to negotiate the listing, sale, exchange, purchase, or lease of real estate;(iv) lists or offers, attempts, or agrees to list real estate for sale, lease, or exchange;(v) auctions or offers, attempts, or agrees to auction real estate;(vi) deals in options on real estate, including a lease to purchase or buying, selling, or offering to buy or sell options on real estate;(vii) aids or offers or attempts to aid in locating or obtaining real estate for purchase or lease;(viii) procures or assists in procuring a prospect to effect the sale, exchange, or lease of real estate;(ix) procures or assists in procuring property to effect the sale, exchange, or lease of real estate;(x) controls the acceptance or deposit of rent from a resident of a single-family residential real property unit;(xi) provides a written analysis, opinion, or conclusion relating to the estimated price of real property if the analysis, opinion, or conclusion:(a) is not referred to as an appraisal;(b) is provided in the ordinary course of the person's business; and(c) is related to the actual or potential management, acquisition, disposition, or encumbrance of an interest in real property; or(xii) advises or offers advice to an owner of real estate concerning the negotiation or completion of a short sale; and

I now track my final sales cost against my original estimated ARV against what the best/closest comp was when I first did my ARVs. 

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.

As the options come in you or someone needs to analyze their potential, do a drive by, get in to see it, and then someone would need to estimate the rehab - a quick way to do this yourself is ask three different GCs what their price per square foot is on a full gut and average them out and use that price per square foot for your rehab estimates.But let's say you get a funnel started and even analyzers to pick out the gems among the muck, now you need your contractor to come in and give you his estimate and then you need your financing lined up and get your term sheet based on your offer, the rehab, and what you think the ARV will be.