If you want to get wireless from TWC the cost varies, The above expert is correct in that it runs about $10 a month for the service (the router is free and part of the modem charge). In other markets the cost can be less and in a few are free depending on the level of service you have. You can always buy your own to avoid the charge and they range from $30 to $80. You can avoid the charge but the downfall is that although TWC offers free support on it's internet service, if you own your own router the support is limited. I hope this helps too :)
other experts are backing this answer
Enjoy TWC Better
Time Warner Cable
A long time employee & expert in nearly all things TWC.