Mega WiFi Advice

Hello, I have a project, where I want to connect to a WebServer from my Arduino Mega. I want to do two things:

  1. Have Mega send a string of about 50 characters in a header
  2. Have the Mega receive a string of about 15 characters in the body of a different webpage

We are talking low traffic here, each request is once every 5 minutes. And speed is not important.

The WebServer is PaaS so I sort of have control over it. But I have full control over the content anyway.

I have WiFi Internet available at the location of the Arduino Mega. I do not want to host a webserver on the Mega.

Can someone please suggest a reliable but cheap WiFi module/shield for this? From what I see they range is price by a long way. I am in Australia so ebay would be ideal.