If you compare with the prices in europe it is affordable using this subway here. You only pay maybe 10-15$ for a long trip between Wuxi railwaystation and Pudong airport. However, you'll need to change once at Hongqiao Station. Here you could choose either the high speed train or continue with subway to Wuxi railwaystation.
You'll find english timetables on ctrip.com>>>
Avoid going in the morning or afternoon when everybody is going to or from work. In the middle of the day you'll get a comfortable trip to your destination.
Since a couple of years the messages on the display is also in english. And you'll get an english speaking voice that tells you where you are and next stop.
The most convenient way to buy tickets is by these ATM:s you'll find on the stations. You also needs passport here and have to go through a security check on the subwaystations. 
Usually you'll find a kind of display on the wall who tells you where you are and next station.
This is how the subway tickets to the Pudong airport looks like.
Tripadvisors tips on what to see in Wuxi China, travelchinaguides tips
