OK.. Let's look at the current situation now. The miners are getting as much as 10 BTC from just transaction fee, from each of the blocks which they mine.
If miners are doing enough effort to spam the network, they'll fetch like 3-4 BTC per block, in an ideal situation (ideal for the miners obviously). In some cases you see blocks include massive fee amounts, but that's more a mistake from a user/service playing around with manually created transactions. It from time to time happens that you'll see these large block fees pop up, but it's not a frequent occurrence. If the network isn't operating under a huge load of spam, blocks mostly contain like 0.5 to at most 1 BTC in transaction fees.