can i just confirm esaint, these are $2 a packet. I got 2 at the newsagent today and were surprised at the low price. No players that i knew the name of (Except O'Shea for MU)
There are also Limited edition cards (only avaliable in certain products or box types) and signature cards numbered out of 100 (Theo Walcott) or 1000 (Shay Given & Kolo Toure)
As for value it is hard to say as these are pretty much like Teamcoach cards and arn't released as a high end product it is mainly just for fun.
But there is a huge range of cards and a huge range of players so it is hard to put price on certain cards.