You have received three window wall subcontract bids. The low bid of $$500,000$ was from an unsolicited subcontractor. They did not fill out your prescribed bid forms. They neither acknowledge nor deny the bid documents or addenda. You know nothing about this firm. Their bid does not state any exceptions or qualifications regarding their proposal. The second bid of $$600,000$ is from a glass firm that you have worked with prior on other sites, but not successfully. The quality of their work was fine, but they battled with your office with respect to contract issues. They were short$-$listed and requested to bid on this project. They filled out your bid form, but their proposal came with an extensive list of exclusions, assumptions, and qualifications. The third bid was also from a local glazing firm whom you had solicited a proposal from and have worked with successfully. Their bid is exactly per your prescribed bid form. They do not state any qualifications or exceptions to the bid documents. Their bid is $$700,000.$ Your pre$-$bid budget was $$600,000$ for this area of work.

What do you do$?$

How would your answers differ if this were: $($a$)$ a lump sum competitively bid job.

$($b$)$ a negotiated GMP job?