I go into these flips thinking they will be full gut rehabs, and if we can save anything it's a bonus.

If you want to incentivize, you can offer a bonus based on the timeliness of the completion of the reno. 

There are 2 ways I determine this.1st is sign up for airdna.co but it's a bit inaccurate.

I'm looking at a multifamily 4 unit with a "bonus" basement unit in Illinois. 

Buy it based on the current number of units, and if you can add one more in the basement then consider it a bonus, but don't base your offer/purchase price on the assumption you'll be able to do so.

Sign up for a free/trial account with the three that seem most attractive to you, then run them through the ringer.

Make sure you don't sign up for any cards with annual fees and that the introductory period is a reasonable amount of time (typically 1 year or longer is desired).Use a credit card liquidation company to liquidate your credit cards (reach out to me for more info).

I see there are several apps or services I could signup for to streamline the process.I am looking for some of the communities experience on what works and doesn't work what you like or don't like and any recommendation you may have.Ultimately what ever I choose need to be user friendly for both me and the tenants.

The bonus deprecation allowed by the 2017 tax act has opened up many opportunities for investors to do better without a 1031 exchange than with one.

Another option in place of the transaction fee is adding a bonus on your end when a transaction does go through.