The Enhanced Client is free. It will take a while to get used to it, but when you learned how to handle it, it has lots of technical advantages (like customizable hotbars for all kinds of complex macros, resizable map, works on any screen resolution, zoomable game screen, smooth movement etc.). You need a 3D graphics card though, but a mediocre one with 512MB will do.
I wrote something about how to customize that client
here, which may be useful for you although the client has received several updates since then.