While you've given a lot of good advice here, I don't think it wise to just use any cuff. Yeah, for all I know, it may be made by the same mfgr. as the Omron ones. Or it could be a cheap sh*tty knockoff which doesn't work properly. And I don't know if they're all identical in terms of how they react to air pressure. No, I don't think a B/P cuff is something for which I want to buy a generic. I'll wait until I can find a genuine at better price.
Again, for those who didn't notice the first time I posted it, there are NO B/P meters @ 40.00 in Canada. Maybe in the US, but I don't live in the US.