It is hard to say. I haven't seen much tannoy mention around here but I have read a little about them. If those are tannoy mercury f4's then the 2 minute research I did on them priced them @ £120 to £400 used. I have no idea how pounds convert to Canadian currency but going from what I offered, what you know about these, I would venture that you base your offer upon how much you're willing to spend and not regret if you don't like the way they sound/produce.
butter and jelly please.