Half pagers take me about 3 days if things don't go wrong. One day for references, tight sketch and maybe basic colours, one day for the bulk of the rendering, one day for the rest of the rendering and final touches. I'm pretty sure I'm on the slower side of things. I'll parrot something someone told me before, though, "First get better, then get fast." Getting better will make certain things easier and faster, where as trying to get faster might just end up making things look muddy.
Thanks for the reply, you confirmed something I'd already read today actually, the thing about painting better and slowing down. I definitely need to take more time with my work to see better results. I think 3 days is good for a piece like this! Thanks for the advice and insight