It's very difficult to determine your case. The more unique the saying the more challenging it may be to trademark if someone else has it and the saying is a famous mark and is accorded that status. With regard to your registering a mark, you have to pay for each "class" you want to register. If someone else has a mark in a different class, you would have trademark issues, e.g. you own a mark for "Acme" for a barbershop and you wanted to expand it to Acme Frozen Foods which someone else has. Good luck with your filing and I would definitely speak to a trademark specialist first for something as important as this.