When you say a drop in trigger, I am going to assume you mean an entire drop in trigger assembly.
The only full drop in assembly I am aware of thats sold in Canada is the Volquartsen one, and I have not seen it for much less than $299 in Canada.
I recently purchased a Hornet Products Custom B drop in trigger assembly from a CGN member, they are $90 on Hornets website, so they would land in Canada at a decent price.
After installing the Hornet on one of my 10/22s and comparing it to a trigger job done with a Volquartsen action pack I really prefer the Hornet.
The only other drop in trigger assembly out there that I am aware of is made by Kidd, and from what I recall it was around $300 US.....but I cant recall for sure.
I would gladly recommend the Hornet trigger, but since I have not tried a complete Volquartsen assembly I cant say if its better or worse, I can only tell you that its much less expensive.
Theres lots of great 10/22 kit out there, but sadly it seems most of it has to come into from the US. It would be nice to have a Canadian Dealer who would stock all the gear, but I suspect the margins would be so slim that it wouldnt be worth their time to do so.