I have a 27″ cintiq which is an upgrade from a medium intuos…
because I already had developed my drawing skills on paper it was easiest for me to have pen on monitor
the tablet and monitor always caused a disconnect in what I was doing…
if you are learning for the first time then the disconnect might not be as bad…
I would recommend the larger area is also dependant on how you learned or what your skill level is…
as for the cost you pay the money, you make the choice…
the wacom cintiq is the priciest option but I haven’t been sorry for getting it…
hope this is of further help