The mousse is about $20 a tube from the dentist. Much cheaper than hundreds of dollars of dental expenses. The gum is dearer but I order it in because I find it more convenient. I buy 2 large tubs and it lasts ages but I can't remember how much they are.

You could ask to make an appt with a dental hygienist, they will clean your teeth and advise you on how to clean and floss properly. Improving your teeth might also mean you have to give up drinking diet or regular soft drink or juices unless you clean straight after, and if you have reflux or have had it during pregnancy or you sleep with your mouth open that can wreck your teeth too, so worth talking to them about what you can do about that too.