Don't do appraisals. It's like asking your mother if you are ugly. I will guarantee you that no appraisal service would offer to pay you 10 percent of their appraisal price, so that means it is a useless service.
Most domain names do not have a lot of value these days, as most people are trying to get as far away as possible from the good names. People tend to try to re-invent the language daily with their names.
Stick to names that actually make sense and make it easy for prospective buyers to contact you. If your names are good then you will get inquiries by email.
One of the most useless things in the domain industry is an appraisal for a low-end name. If you have a great name then it would be a good idea to ask a group of experienced domainers what they thought.
Good luck with your names, but remember that 99 percent of the people who pay for appraisals are amateurs who have bad names. Don't be a sucker. Get some great names and you won't need to worry about anyone's appraisal.