The Aquamax range of pumps are the best fish pond pumps in all aspects.  Yeah, they are more expensive, but they will save you money in the medium to long term.

OASE have spent literally millions of euros, making this pump the most energy efficient in its class.   Filter pumps have to run 24 hours a day, 365 days per year, so they can impact your energy bills significantly if you choose the wrong one!!  An easy way to think of it is that every watt of power will cost you more than $2 per year.  

If you purchase a cheap Chinese-made pump, they will typically use around 200 - 400 watts of power, so you can see the Aquamax will, in fact, pay itself off in not so long, especially considering that these units are built to last, unlike its poorer cousins...  

These units are German made and show confidence in their product with a 5-year warranty.