When you both tell the budget and list out what you want, then the professional can figure out if you are aware of the real project cost. I met many customers that do not know what they are talking about and did not have realistic needs compared to the budget. That is a waste of time for both sides. When you are aware of the cost reality, that is great point for negotiation. Remember, with a reputable contractor you get what you pay for.
Always start with what you want and then, when you get the bid, you can either add or remove certain things to fit your budget. Also, talk with your contractor because he will know how to make everything fit into your budget.
Great question. I recommend sharing your budget with the contractor. If you do so, however, be certain you get multiple bids. At least three. Then, hire the contractor you most trust, not necessarily the cheapest.
Share your budget with the contractor. It doesn’t benefit either party when information crucial to the project is withheld. If I was remodeling my kitchen and I thought it would only cost $30,000 I wouldn’t want to waste all my time and effort, or the contractors, only to find out after many hours of work and planning that I had an unrealistic budget and can’t do the work.
After meeting with GC and walking through all the details you want done, the GC will have an idea of how much the project will cost with you. Tell your budget - it will be very helpful so you both can be on the same page and you will be able to cut some unnecessary cost.
You should ALWAYS let your General Contractor be the Lead and use a CM contract with fixed percentage and a transparent budget. If you want to incentivise the GC, throw in a cost savings split that enable them to make more from saving you more that charging you more.