New to this site. My first thought is to the "DIY throw a bathroom together in a weekend" comment makers. Your comments about how much it cost you 2,000 to do a bathroom in your home correctly or incorrectly without a picture of the finished product is invalid in this forum. I had a customer spend 2k on a complete vanity, dumb comment. Second, I've agreed to the home owner supplying all the materials (one time mistake) and it was a total disaster after getting into the project. We know what we need when we go for supplies....plain and simple. A homeowner that purchases materials for a remodel they CAN'T handle for a contractor that CAN complete the task is like a mechanic ordering a transmission for a rear brake job....irresponsible. A good contractor listens to his customers, is given a budget, and decides if it is profitable for his company. If we give you a $7,000 price for a bathroom and you think it should be done for $5,000, I encourage the customer to get 2 more bids. I have faith in the quality of work I do, and if the customer doesn't see that from the very beginning, the transaction will be a nightmare. "JOE" your comment stuck out because its the unseen labor hours of modifying the old to fit the new that customers don't and will not ever understand. If you want something done right in your beautiful home, have the money set aside and then hire a contractor you trust to make your happy.
A punitive approach to what could be unforseen and atypical delays may be a bad idea. I would suggest offering a bonus for the job being completed early rather than a penalty for it being delayed. If material is ordered, we can't make it arrive faster if something delays the shipment. We recently ordered a bathtub requested by a customer. It was promised by our supplier for a Wednesday delivery. Bad weather hit Texas and it just didn't leave the warehouse until the following Monday. It blew up our schedule for the project and it wasn't anyone's fault or mistake. If we have an employee critical to the project get sick or injured, we may not be able to get things done as originally scheduled. Jobs can get off schedule for a lot of reasons outside the contractor's control. Charging them for those things is likely to turn them away.
The things that may scare someone away is agreeing on cost and deadline before they could know what they are getting into. The last thing they want is for this job to cost them money. I think a good way to talk about deadline and reimbursement it to tell them your concerns. Be honest, tell them it is costing you time and money having to shower somewhere else. Ask them if it would be possible to be reimbursed if it goes over deadline. If they agree put it in contract. What I think the trick is, is to bring up the topic and let it be their idea or have them agree to an idea rather than coming to them with something seeming like demands. Offer a drink or something, seem friendly and easy to work with. Kindness goes a long way. Their reputation is on the line not yours.
There are a wide range of costs associated with remodeling a bathroom, including size, the type of materials, its current condition, and the location. Homeonwers spend on average between $15,000 and $25,000 in their bathroom renovation. For example, the average cost of a 100 square foot master bathroom with tile walls and flooring, new fixtures, double vanity, and walk in shower with separate tub is around $20,000.