Good luck on your quest for a ram. Without getting too specific regarding costs because there's just too many variables and as you say your trip may be a few years off, here's a few things you can count on:
Canada dall hunts cost around 50% more than Alaska hunts. That is simply a function of supply and demand and demand for Canada hunts is greater because they have much higher success rates.
In the end a Canada or Alaska trip will cost around 35% more than the listed hunt price. Lets say you book a 22k sheep hunt in Canada + 1500 airfare to Whitehorse + 2k air charter to camp + 1k for licenses, meals, hotels on the way there and back + 1k for taxidermy and shipping + 1k for taxes and misc hunter/habitat funding. Now your 22k sheep hunt is 28.5k (maybe more, maybe less) and we haven't talked about the thousand(s?) in tips. Notice I said thousand(s) in reference to tips and not hundreds as that is what the outfitters would say is appropriate.
Airfare, charters, shipping and taxes are all a little cheaper in Alaska but you can still count on a 14k hunt actually costing around 19k.
These figures are approximate and I'm sure there are a thousand stories on this site and others about how a hunter got this and that for less money. Absolutely possible...
That brings up my next comment. Listen cautiously to the success stories of others! As you research for your hunt you will hear dozens of stories by hunters that harvested a sheep and "found a bargain", went on a last minute cancellation hunt, hired a hungry new outfitter etc. These stories are true and congratulations to the hunters but they are the exception rather than the rule. When a hunter harvests a ram he is anxious to share the tale over and over. If a hunter saves a significant amount of money in the process, that is conveyed in the story. The hunter that went on a fifteen thousand dollar camping trip and returns home empty handed licks his wounds and he doesn't have anything to "brag" about. You will be doing yourself a huge favor if you realize that stories of successful hunts are relayed 500 times more often than the stories of failure. So don't start to assume that sheep hunts are as easy to pull off as some of the stories would have you believe.
Last piece of advice, research, research, research. A little time on the internet will tell you that southern AK had a brutal winter 3(?) years ago and mature rams got a little harder to find. More recently northern AK and parts of the Yukon are experiencing significant declines in sheep populations. Look it up, Alaska residents are clamoring to find sheep. It's unlikely that the number of sheep hunters will decline, the pressure on a legal ram will increase.
Good Luck!