A spellchecker for my iMac

The spell checker in Appleworks 6 has not the ability to check my often spurious spelling as I am typing. It (Appleworks) is rather clunky and I would like a word processing software, or separate spell checker program that would keep me on the straight and narrow, while typing of course. Problem is that the comments I have seen on Marinerwrite 3.7.2 and Grammarian Pro X 1.7 sort of scare me. Some good, but some really bad stuff happening. After using a computer now for a very few years I am still quite intimidated by all the technical words and therefore fear putting some unknown thing into the computer and having it wiggle itself into a nervous breakdown. I use the word processor about every day and would really, really, awfully appreciate some help in finding a spell checker that would check as I type or a word processing program which would accomplish the same thing, SAFELY. Or is there such a thing ? Price is no object, merely a critical factor. Something up to about $50 to $70 would be fine. I'm rather leery of stuff that is free, you get what you pay for. Can someone help ? I know a Mac ain't the norm, but it is a cute little feller.