After reading through the forum I concluded the same, the other buyers offer for $625,000 was as high as someone should bid but it was rejected.

You will get the full 12% if you hold the property for a full year otherwise you will only earn interest on the number of days you have held the tax certificate / deed.Please correct me on this if I am wrong.

@Guillaume DerouetI assume you're talking about an uninsured investment property.If so, the two correct answers are: 1. not quite and 2. it depends. 

So (700-574.13)=125.89 cash flow after expenses so 1510.44 a year.  1510.44/7350= .20X100= 20.5% CASH ON CASH. so is that calculations correct?

I understand mostly on auction website Investors bid on property with cash.

Get multiple bids. 

@Felix L PerezWhat @Basit Siddiqi said is not necessarily correct.

., but just getting the winning bid is super difficult.

But all in all, i'd have to agree with @John Underwood and get it done correctly, even if you have to work out a payment plan with the plumber/vendor.

I have spoken to a developer and he provide me a verbal bid of 108K for a 1500 Sqft house with two card garage. so the total sqft is about 1900.