"Foreign country" and "higher taxes" get thrown around by Jays apologists as reasons some free agents don't want to come here. (same goes for guys who block trades).
As we know, Canada isn't that foreign and it's been shown that Canada/Ontario taxes are not the highest in MLB. More like 8th highest out of 30 teams IIRC. Plus, that gets watered down by being taxed everywhere you travel (This was discussed at length during the RA Dickey extension talks)
Bottom line, most realists think that 20 years of losing is the biggest problem. Not the thought of living in Canada for 85 or so days a year or paying higher taxes than you would in Florida.
The problem isn't unique to us. Guys don't want to sign with perennial losers like Minnesota or Houston either.