Services on the Handy platform are priced hourly, and there's a two hour minimum for most handyman jobs. Depending on the size of the job, it may take more time. You are always free to negotiate changes to the job, including additional payment or scope, with your Pro. Materials are extra, so if you're getting something like drywall repaired, you need to provide or pay for the drywall, or arrange for the extra materials directly with your Pro. Same with a TV installation.
To get an estimate, select the service you need by making a new booking and follow the instructions. You'll be given an estimate based on the details of your job before checking out.