I'd like to see which brick and mortar stores were complaining. When I buy computer components, I don't have much of a selection here. That is unless I want to pay $40 more for the same component.
I just re-read your post. Apologies I did misinterpret what you meant. So it seems you want to get the best out of LoL with a good graphics card. That shouldn't be a problem considering that, as mentioned above, it is hardly intensive and difficult to run.
Seeing as the H97 doesn't support DDR4 RAM, then out of $230, you'll be getting DDR3 RAM which are pretty cheap nowadays.
I compiled a list of the parts that you have now and added RAM + Storage. Take a look yourself:
http://pcpartpicker.com/list/VFGk6X
Note that the 8GB of DDR3-2400 RAM as opposed to your 8GB of 1600MHz RAM on top of the 1TB Seagate HDD both add up to a bit under $100. So that left you with about $130-135 give or take for your graphics card.
The GPU isn't included in the list because they don't have price listings on the site for GPUs suiting that price. But I did search on Amazon and found a few for you listed below.
If you're willing to push the budget a bit and throw in a few more bucks you can go with this: $145 GTX 950
Or you can stay within the budget and stick with less powerful GTX 750 Ti: PNY XLR8 GTX 750 Ti
And if you're fine with buying used products that deliver more power than both of the graphics cards mentioned above: GTX 760 Superclocked
I don't know what graphics card you're packing right now. So the ones I picked out may not be comparable to whatever you currently have. Hope this helps you out a bit though!