The tricky thing will be to find a single malt in that price range. There are a lot of cheaper whiskys out there that are responsible for a lot of people having decided they don't like whiskey. Things like Teachers, Bells, Famous Grouse come to mind.

So far the lowest-priced single malt that I have found up here in Ottawa is "The Singleton of Glendullan". It retails for about $50 here, or a little over half of what a bottle of a'Bunadh would set me back. It's a Speyside (I'd agree with Maddafinga's suggestion of starting with a Speyside) single-malt, and while not as good or complex as its more expensive neighbours, it's pretty darn good.

There are plenty of places online that give reviews of whiskey, this is just one:

Glendullan Single Malt Scotch Whisky

Happy hunting, and whatever you try - enjoy!