Here is the completed dialogue:
A: My laptop is __too__ slow to play video games. I need a new one.
B: Look at this laptop. I think it’s fast __enough__ for games.
A: It isn’t __as__ small as that one, but I like it.
B: The size is a problem. Can you put it in your bag? It’s __too__ big.
A: Yes, you’re right. But it is __not as__ expensive as a laptop. I can buy a new bag.
B: That’s true. Look. This laptop bag is as cheap __as__ a schoolbag! It’s a special offer.