For what its worth I bought one of those cheap pumps off ebay and it worked fine for about 3 weeks. I came back one day to find the pump had seized up and the power board had auto cut out.

I would recommend NEVER plugging your pump (or heater) directly into the wall or extention lead but always run it through a power board that has auto cut out (which is most new ones these days). Your pump may have auto cut out built in - but a power board is likely to switch off well before your pump might.

I now use a pump from bunnings which cost $149.00 - it runs smoother and has more power and is much better built.

You get what you pay for.