There is a lot in what jnb-rare says, if you have set your heart on something and are then forced into a compromise, usually for financial reasons, the compromise never satisfies, it hasn't got a chance, because your always thinking about what might have been. Over a period of time differences in cost price errode and you are for ever kicking yourself. When I was younger I once bought an Alfasud, when what I really wanted was a GTV, good as the sud was, it was never going to be the full deal. If your friend really wants a Birdy tell him to save up (and maybe allow some extra for a pair of gloves), or else give a full suspension Downtube a try.