Our usual bank wouldn't do more than 80%

Retired police/military/firefighters/contractors/plumbers/etc. or other folks who are retired but want some "extra" money for hobbies are good sources for finding someone willing to do smaller jobs. 

The boundaries of a neighborhood can be larger streets, tracks, parks, etc.A house as close as possible in features (beds, baths), size, etc.Using the same financing method, with an arms-length transaction.Once you've found the right comps, then you have to make adjustments to them based on all of those features to get an accurate value for your property.I used to use a spreadsheet for that, until I built this tool: www.reikit.com/compsThe tool uses Zillow data for lookups, but usually I go in with my own set of comps from my realtors then use the tool for adjustments.The hard part is getting the comps, though, and MLS is always going to be king.Cheers!

@Sam Stout what class and price range do you usually buy in?

On the other hand, if your agent had showed you another 20 houses, would you be offering to pay them extra commissions?

Other than the closing timeline (which is usually longer for financing), it really doesn't make any difference to the seller. 

Property management companies charge one of two ways usually, a percent of the rent or a flat rate.

My analysis is just a bunch of numbers tossed into a spreadsheet (based off of many others I've found), so there isn't any extra work on my end.  

The usuals like VRBO, Airbnb, and Homeaway are being joined by Vacasa and a lot of geographically local efforts you can find.

I include another month of holding costs in my projections to accommodate extra time needed to close on the pre-sale.