I currently use D-Link http://www.amazon.com/D-Link-DCS-930L-mydlink-Enabled-Wireless-N-Network/dp/B00452V66G">DCS-930L</a>. While it is not the greatest out there but it's sufficient and it's wireless. You can get free app from D-Link that works good enough with that camera and you can also access it on the web.
I also fiddled with [IMG]https://market.android.com/details?id=com.rcreations.ipcamviewer&feature=search_result#?t=W251bGwsMSwyLDEsImNvbS5yY3JlYXRpb25zLmlwY2Ftdmlld2VyIl0.">IP Cam Viewer Lite</a> which is free and the list of supported devices it huge -> [IMG]http://hit-mob.com/ip-cam-viewer-android/device-support-list/">Here</a>. I'm sure you can find a camera in that list that can fit your budget.
I also fiddled with [IMG]https://market.android.com/details?id=com.rcreations.ipcamviewer&feature=search_result#?t=W251bGwsMSwyLDEsImNvbS5yY3JlYXRpb25zLmlwY2Ftdmlld2VyIl0.">IP Cam Viewer Lite</a> which is free and the list of supported devices it huge -> [IMG]http://hit-mob.com/ip-cam-viewer-android/device-support-list/">Here</a>. I'm sure you can find a camera in that list that can fit your budget.