[Steve]

It's very easy to make your own.  You need: 4 cups cane sugar 2 cups of water 1/4 tsp citric acid (available from LHBS) Here is a pastry chef's recipe, much like Punatic's (with some differences). http://www.chefeddy.com/2009/11/invert-sugar/ The recipe is half way down the page. There are some photos with metric conversions.   He writes that the sugar can be stored for up to 6 months in closed container in the fridge so you could make a load of it.

[tygo]

Sugar ferments faster and cleaner when it has been inverted first.  The yeasties can concentrate on fermentation only instead of conversion and fermentation.

That's the theory.  In real life brewing I haven't found that it makes any difference.

I haven't used invert sugar so I can't say whether it makes a difference from my personal experience.  But I've never had any problems with the yeasties tackling a beer with 20% sucrose.  I've got one like that in the kettle right now as a matter of fact and another carbing up in the bottles as I speak.

[tubercle]

For brewing purposes it doesn't matter. Its a waste of time

Why is there a market (us!) for $8/lb. Belgian Candi sugars?!?

 Marketing (see also: P.T. Barnum).

If there wasn't a demand there wouldn't be a supply. Economics 101.

[punatic]

Sugar ferments faster and cleaner when it has been inverted first.  The yeasties can concentrate on fermentation only instead of conversion and fermentation.

That's the theory.  In real life brewing I haven't found that it makes any difference.

Brewing?  Hmmm...  I hadn't thought about it that way...