I bought Dragon Age Oriigins through GOG. Now I want to buy Dragon Age Inquisitions and bring along my character. But, GOG doesn't sell Inquisitions. If I buy it from another source, will I stll be able to import the character?

Inquisition uses Dragon Age Keep for its save imports.

Forgive my ignorance, but does that mean yes, I can import the character?

It's a website where you upload your DAO and DA2 progress. It then allows you to customize that save (if you want) and produces a final something that exports to Inquisition.

Basically it's a save state generator.

https://dragonagekeep.com/en_US/

So yes, you can import your character.

I wouldn't bother. Da: o was a great game, da2 however was truely awful. Da:I was better, but it gets dull real quick. Repetitive quests, mmo like world full of repetitiveness, no real questions or point. Didn't bother finishing it. Save yourself the time and play something else.

Thanks I am getting ready for the Landsmeet right now, so time will tell. I tend to be a completist and generally follow thru to the end.
But thanks for the comment

I should note that you don't actually play your character. They are only mentioned in stories and whatnot and their actions in da:o change the world somewhat in da2 and dai

If I were to go to the touble of importing a chacter do I get the skills, attributes, money, etc.
If not, what is the benefit?

It only affects the world state (who you supported, who you didn't, who may be alive or dead, and a few other things like that).

Thanks for that information, a better way might be to adjust the new game with the old stats to enable starting with my lvl 20 Mage

What character ? You're playing with an Inquisitor, not the Grey Warden from the first game, or Hawke from the second one. It's the choices and world state that carry over, not the protagonist, least of all stats and level. For this, you have to use Dragon Age Keep (you need an Origin account). Don't use if you haven't beaten yet the two first games with all the expansions/DLCs as it contains massive spoilers.