We hired a contractor to pour our concrete slab. He came to see the site, received a copy of the site plan and specs relating to the slab. Later [same weekend], he texted me a price of 17000 [and listed various things it included such as machine rental, skid steer, labor, etc.]. I even met with both him and the steel building contractor who would be erecting the building just 2 weeks later after we agreed to hire him. This was in June, in the end of September, the job was finally finished [not due to our delays, but his]. At no time during this entire 3 month period did he attempt to tell us that he needed to renegotiate the agreed upon amount or that it would be higher. He was billing on a monthly basis, which we paid quickly. I was keeping track of the bill totals. His one email about any specific money amount was to ask us to send a check for 11,000 for the concrete. His final bill was $4700 more than what we agreed to pay [including a price of 12,600 for concrete and he listed the 11,000 as a prepayment with no explanation of why he was billing us 1600 more than he told us it would be. Once I emailed him and said we never agreed to a new 27.6% increased amount, he made all kinds of excuses. Our site plan never changed, the slab he poured is the exact same size as was made available by the steel building manufacturer. Instead of pouring the entire slab in a single pour, he insisted in making the porch into a separate pour, later, that was his excuse for part of the increased amount [which is confusing, how can it cost more to pour on a different day]. In addition, one of his reasons to pour the porch separate was so he could re-use the forms from the larger section of the slab, yet in his final bill, he charged us again for form material. I have documentation of all of these amounts [in both texts and emails]. We have paid him in total the 17,000 we originally agreed to. My question is if he attempts to file a mechanics lien, would it stand?