Offer other suggestions for parts.
I've done a few mock builds using this and it only seems to offer Gigabyte products for motherboard and GPU selections, NZXT for cases and PSU, and Crucial 8GB DIMMS for RAM.
This is because of a mixture of things
a) Gigabyte make some very good motherboards at different price points. There are some other manufacturers thrown in at the low end but if Gigabyte have the best options for the money those are what will be recommended
b) The NZXT case is the cheapest and cases only get upgraded if nothing else can be. This means that you will see the source 210 a lot at the different price ranges
c) RAM is RAM. There is little to no difference to performance no matter which you pick so I choose the cheapest and recommend that.