why buying from people when you could pay directly on steam because they're now accepting bitcoin as their option,although when you buy from people you'll have to make sure about their trust and the balance you'll will be only little bit higher
but if you're forcing,go to digital goods section,you'll find out there
Probably he is looking to buy it at cheaper price here.But yes I would suggest op buy it from steem for you may get into trouble in trying to save some small amount
I think a little difficult to find sellers steam wallet at a cheaper price, because if the seller is not in need of quick money I think they will sell at the same price with steam or even be more expensive. But I personally also be advised to buy directly in the steam because it can be said to avoid scams by people who are not responsible. IMO