Estimating jobs...

Understand what you are going thought and have seen the same thing happen on the large restoration jobs, the customers get shell shocked when it comes time to pay the bill.

I have heard of a good way of going about it. It is to do the project in stages and get paid in full at the end of each stage.

Examples as follows:
Bring the car in and talk it over with the customer and give them a general idea of what they are getting into.

If they agree and want to continue go to stage 1.

Stage 1: Open up or Tear down the car to reveal any additional work that needs to be addressed, now get paid for this.

Stage 2: Clean up all rust and or decay areas Including soda blasting/sand blasting and then prime the car, now get paid for this.

Now the customer has a good idea how the project is coming along and sees results and has opened his wallet so now he has skin in the game.

Now all agree to move forward go on to Stage 3,
If customer does not agree, the customer may stop the work at this time as he has paid for everything up to this point and it is his decision.

Step 3: Weld in all missing steel and corrosion repair areas fixed. get paid for this.
Step 4: Now is the time to shape up the exterior bodywork filling and straightening process getting ready for the paint work, now get paid for this.
Step 5: Primer Surfacer work over body work, block sand out to get straight for painting and remove all scratches, now get paid for this.

On and On, each stage you complete get squared up and paid. This allows you to let go of the worry of getting paid for your previous work and allows you to concentrate on the next steps of the job that the customer has hired you to do. If the customer wants estimates for each stage as you proceed, it is a lot easier to estimate one stage at a time as you are going through it than it is to estimate the whole job sitting out in somebodies driveway at the start of the job. Complete the stage, get paid for it. Then estimate the next stage and continue on.

As any business you have to build up your reputation and following as people become more and more happy with your workmanship, then it goes into supply and demand as your schedule starts to fill and you get a backlog of customers then you can start to raise your prices as people are standing in line to have you do the work for them.

So as you say: I would love to just bid by the hour
You can develop a track history of the stages with photos to show customers that this is what it cost the last customer to do Stages 1,2,3, &4. If they like what they see and can afford it, then bring them in as a customer.

If they can't afford it, better off not getting involved in project in the first place. Try to find some quicker turn around work, get paid and keep building your business.

Hope this helps . . .