Originally Posted by
WorldLux
IIRC the Intercontinental ANA Tokyo sold me the combo ticket for Toei/Tokyo Metro slightly discounted. If you're using the metros a lot, it will overall be cheaper.
Entirely possible but the Suica can be used for many other purchases besides the subway, including surface trains, convenience stores, some museums, etc. I suppose he could save a little by carrying both cards. YMMV.