How do you estimate the cost of your work with inaccurate TOR?

Question

Freelance

Good afternoon!
I work as a freelancer 1C and always face this problem. Which is expected, but now I wanted to talk.
A customer appears with the task to ask for an estimate of the cost. Estimating the cost of performing work means estimating their duration. In my experience, the duration can only be accurately estimated if a similar task was performed almost exactly the same. For example: change the layout of the site, add a plugin, create a site based on a template. In 1C, for example, this is to update, write a printable form, reload data.
In other cases, when an atypical task arises that has never been performed before (not only by me, but in principle), the duration of work and cost can only be estimated approximately, the more accurately the task is detailed and divided into smaller ones. But according to the general impression, it is almost impossible to say exactly until the day that for so much it will be completed.
On the other hand, when you are interested in what your budget is, no one most often can say how much you are willing to spend.
I just don’t want to deceive the customer or expose myself, so I come to the conclusion that it’s most correct to sell my hours of work on freelance. Let's say from 13 to 18. During these hours, work takes place and the customer can contact me and make sure that the time spent is effective, as if the employee were sitting in their office.
Or work on typical services.
Otherwise, there is a big risk of setting yourself up.
Tell me how you work with the customer (on time or not, what do you agree on first, when you receive payment) and how best to build relationships?

Answer 1

Usually I specify a range of prices. Of course, it is impossible to say the exact cost until you see the full terms of reference, so think about the maximum amount you will do the project, and from this already build a fork, for example, from 20 to 28 tr.
No one asks you for an exact price, if a client submits a project for evaluation but has not yet written a TOR, then he hopes to find out an approximate budget.

Answer 2

I usually write a document for the client in which I list the tasks for the project and estimate those that I can estimate. In the same tasks that are not 100% clear, I write that the time is to be determined, and, if the context implies, then I immediately discuss them along the way. I also write a fork when there is some kind of ambiguity like "go to the server and see what's really going on there." :)