Hitch - it works out more expensive as it either doesn't last as long, or do as good a job, or you need to use more each time, or you soon get pissed off and buy something decent!

Tom - Polish you work/rub, wax you apply lightly in straight lines.
Only applying it to sit on paint, as opposed to trying to achieve and cleaning or correction.
Wax is after polish, wax is your last stage to seal and protect the paint.