But just running all the basic formulas; the 1% rule, the 50% rule etc nothing comes anywhere close to adding up. 

I know it varies but does that formula usually work?

It's always wise to be conservative when doing your estimates (both on rehab costs and ARV) so let's assume $220k ARV and $100k rehab costs$220k * 70% = $154k - $100k Rehab cost = $54k Offer...In my opinion a $40k range of ARV isn't acceptable and you should narrow it down so you can have a clear idea of what you can offer and what you can't.A more precise flip formula =Max Purchase = ARV - Rehab - Fixed Costs - Desired ProfitBut again, you need an accurate ARV!

Does anyone know if there are any formulas out there that would help to determine whether a neighborhood is a good one in which to invest in rental properties?

But like every other show, theirs has a formula--out of 3 houses shown each episode, of course the owners always choose the crappiest (which makes for a better show!)

This led me to question whether my formula is too aggressive for my market.Using the 70% rule I would have potentially profited about $150k on the property.

There has to be a formula or some true fire method as to provide at least 80% accurate repair costs to potential buyers.

There are plenty of threads here on formulas for both rehabs and buy & Hold rentals. 3) Learn your market.

However the formula doesn't work for this one because with property management, that and the escrow eat up over 50% of the rent by themselves which leaves nothing for maintenance.

There is no magic formula.