This month I'll partner with my daughter on a Subject To deal in the SL Valley.I've looked a several seller-financed properties both SF and small MF but the sellers are unrealistic about pricing and I have no interest in a negative carry. 

Im living proof of what good guidance can do for people who do not have unrealistic expectations. 

That sounds unrealistic because it's way more than $8,400, which is $700 x 12.Are there more professional calculators out there that don't cost much, or is mine okay?

The last 2 years have seen unrealistic unstainable gains, This advice is what I was told every year since I started buying SFR in 2015.

Flips can be done pretty easily in 7 days if they are simple and as mentioned with planning or a templated plan 7 days is totally doable even for one that needs a ton of work.That being said 1 day seems unrealistic unless they exclude a massive amount of planning before the project which maybe they are.    

@Josh H.Many investors believe/make unrealistic assumptions and often apply those assumptions to the wrong property classes.In our OPINION (always verify yourself!)

Is it even possible or am I being un-realistic in my timeline?

Maybe my disappointment was due to my inexperience and unrealistic expectations.  

RV parks are also very interesting and so are self storage.The problem with MF in the past couple of years is the demand pushing up pricing and the unrealistic proformas that investors were creating.

@Kyle ScholnickI agree with you that the numbers presented on many turn-key companies' listings can be way too optimistic, if not unrealistic altogether.