You mean this?
1. Raspberry Pi 2:
$352. 128 GB memory card: $75.95
3. Raspberry Pi B+ Power Supply: $6.99
4. Raspberry Pi WIFI Adapter: $8.56
5. Raspberry Pi Cooling Fan: $7.99
6. USB to TTL Serial Cable: $9.95
7. Heat sink: $10
8. 125 gh/s USB miner: $93
SD card selection is way too expensive (even when ignoring the potential fakes), there's a heat sink and cooling fan that's unnecessary (already included in the 2x AntMiner U3 selection; which is an iffy choice in itself, but alright), the wifi adapter is generally unnecessary (odds are you'd place this near some manner of network switch/router - throw in a cheap network cable instead, might even be able to get away with USB), the FTDI cable.. why is that even in there? You're supposed to play with the software, not reconfigure the innards of the rpi2 ..and a few bucks could be shaved off the power supply as well - might as well make that a generic USB power wart instead of being stuck with a 'fixed' microUSB output. The rpi2 is reasonably-priced and similar-level alternatives tend to be priced around $35 as well. Not sure that level would actually be needed, but there's better areas to shave cost at least.
You still wouldn't have the software/whatever they're providing, but in terms of hardware, you can certainly do cheaper.