What about the Silverstone Precision PS07? It's a bit more cheap than the Temjin and it doesn't have the 180 mm fan which can't be made very quiet.
You could also consider a very cheap case like a Cooler Master Elite 341 or a Fractal Design Core 1000. Or simply go mini-ITX.
The vibrations coming from the hard drive will probably make a lot of noise even though the hard drive isn't know to vibrate a lot. The hard drive cage Precision/Temjin does very little to reduce noise from HD vibration. So perhaps an aftermarket HDD suspension system.
I like the look of the PS07. But if they fan is so hard to quiet, why does it get such a good review from the sticklers at SPCR? I do know that there are proven quiet 120mm fans out there much more so than larger ones. That case would look sharp next to my HT gear too.
Not looking to go Mini-ITX.
I'm not worried about seek noises. I did build a system 9 years ago with two drives in RAID 0 in an alphonos suspension, but for this machine, hard drive seeks aren't a big deal. The 9 year-old machine has been downgraded from a power user's machine to my dad's web surfing box, and it's not silent anymore after its' fan controller bit the dust, but it soldiers on with the alphonos suspension in place.
@CA_Steve, that looks much better. Well worth the extra $20 IMHO.
So here's what I've got, I think it's much better than the first go-around:
Core i3 3220T - $128
Biostar H77MU3 motherboard - $80
8 GB Corsair DDR3 - $42
OCZ Agility 3 SSD - $99
WD Caviar Green 3TB - $140
SilverStone SST-PS07B - $70
Seasonic 450W - $80
Nexus Quiet fan - $10
That looks like a reasonably priced HTPC build.