Implications of using a knock off ethernet shield

While that old adage of, 'you get what you pay for' come to mind, I feel the need to ask the experts.

I want to get an Ethernet shield for my Arduino, but don't have the 30 dollars to buy a proper Arduino brand one. So the next course of action is to look at ebay knock offs. Usually I am fairly good at deciding which ones are worth while, and which ones aren't, but in all honesty, I know very little about Ethernet. I am hoping some pople could give me opinions on how these look, and some issues I may need to consider if I were to buy any of them.

This seems to be a bottom of the barrel option: http://www.ebay.com/itm/Arduino-Ethernet-Shield-Wiznet-W5100-/121182816716?pt=LH_DefaultDomain_0&hash=item1c370f09cc

This one seems to be a bit of a step up: http://www.ebay.com/itm/Ethernet-Shield-W5100-for-Arduino-UNO-MEGA-2560-1280-LEONARDO-/251323000194?pt=LH_DefaultDomain_0&hash=item3a8404a582

This one looks similar to the previous one, but I am not entirely sure: http://www.ebay.com/itm/Ethernet-Shield-W5100-For-Arduino-2009-Uno-Mega-1280-and-Mega-2560-/300916075105?pt=LH_DefaultDomain_0&hash=item460ffeea61

Any opinion on any of these would be greatly appreciated.

Any shield based on the W5100 chip will be compatible with the Ethernet libraries that are part of the core set of libraries.

But, ask yourself how important it is to support the Arduino team. You are, after all, using their IDE< their libraries, their forum, etc. The only way that they make any money is from the sale of hardware.

PaulS:
Any shield based on the W5100 chip will be compatible with the Ethernet libraries that are part of the core set of libraries.

But, ask yourself how important it is to support the Arduino team. You are, after all, using their IDE< their libraries, their forum, etc. The only way that they make any money is from the sale of hardware.

Ill admit that I hadn’t really taken that into account, and for that reason, Ill most likely wait a bit and buy a formal Arduino brand one. It easy to overlook the details when you are trying to be a cheapskate…

and for that reason, Ill most likely wait a bit and buy a formal Arduino brand one.

On their behalf, thank you.