Well it took some time but Microcenter's i3 2100 & mobo combo finally came back. Just got myself the CPU for $99 and $50 off a motherboard. In-store only.
If you're looking for the cheapest option possible, it's hard to argue against
this CPU and
this mobo for $99AR+tax. It doesn't have DVI or HDMI onboard, but if you go with an external graphics card, it's a pretty awesome value (considering that the CPU alone goes for $125+ on NewEgg).
I'll put together a post later with my HPTC build. I'm going functionally fanless and w/o moving parts. Should be fun.