I've had varying success with yellow letters with the highest response rate about 3%.

Knowing of course that legal specifics can vary from state/locale, do you have an example guarantor contract?

Also, do these fees vary from lender to lender and can you save by shopping around on the closing costs?

@Gino Barbaro  EM  or Deposit money varies.. but traditionally outside of CA it can be rather modest.. 1k to 5k max.unless your in a commercial deal or really high priced..  

How much varies depending on the market and seller. 

Assuming 70% LTV, you could probably walk with around $100k, on which your monthly payment might be around $500(this could vary kind of widely, depending on interest rate, if it's interest only, etc.)In order to justify this strategy, you'd need to be able to invest those funds at a suitable spread.

.:..someone bought a SFH for $2.5 million just to rent $6600 a month... another bought for $1.8m just to rent $4500 a month....I hope they are all 100% cash down... if they finance the purchase, they would be looking at $3000 a month loss easy...That is just the reality of Bay Area...Median prices in Sunnyvale ($1.5 mil) varies from median prices in LA (749K). 

In most areas, perc tests are handled by the local county and/or health department - but the process can vary depending on where you're at.What is the topography of the property?

Property management approaches will vary based on the property quality, location, tenant quality, etc... it is not a one size fits all solution. 

Its good exercise for me, its good for the dogs, and is great for finding leads.I think it still can work, but will vary depending on the area.