Good Idea to be wary of those things but most GC'c want a price that includes what is on the plans. Exlude too much and they don't have a good comparison to what others are bidding.?Plans & Specs?, just bid it like it is. Be clear in you proposal with inclusions, exclusions, clarifications & maybe alternates. Talk with the client while estimating so they know your interests and concerns.
How would you have felt doing it for 112Bid one earlier this year, it went for $112,000, my bid was 126,000