Hi Pip,
I think any and all reputable caribou outfits will cost you $5-7k per person. NWT, Quebec (risky), Manitoba, or guided AK. Mtn caribou even more. You get 5-7 days hunting.
Just a suggestion: Look into a diy AK hunt. It's not as tough as people think it is. You'll spend money (between you) to gear up. Then you'll have air taxi, AK license & tags, and airline tickets. The best thing is you're all set to go every year, and you'll get 10 days hunting for less money per person than Quebec will for 6 days. You'll kill caribou too.
Nice avatar!
Kev