Currently I am mining ltc at 980/1250 @ 1.063
For btc, I can set it to 980/625 @ 1.050, lower than this may not stable.....

A typical monopoly ATM, so they charge whatever they want.

Deathcode, I saw your calculation here and in the other post, nice rig btw.
The only thing I consider is a flaw in your idea of buying coin directly is the price may not go up forever, so the risk of price fall may lead to a huge loss.

Imo, If ppl build a mining rig, at the end of day the worest scenario is s/he end up with a nice gaming machine vs nothing, maybe I am too risk aversion in coin speculation, coz it has less underplaying comparing with stocks or commodities

 
a spare IKEA little coffee table
a unused IKEA table leg
4 unused wheels from IKEA furniture
a pair of bracket from Dollarama

and I put them together, 

what kind of temp you got with this layout? Will they get too hot?

Finally I setup the unit, and add some mobility to it, so I can drag it instead of lift it up

the voltage is really good, my powercolor 7950 reference won't go lower than 1.063v.....

please educate me on this "FPGA is still very profitable" statement, I thought FPGA only has advantage in term of power consumption rather than hash power.

how about buying BTC directly?

if this is not an option for you,

do some simple math

with 6000 USD, you will get approx 12 7970 @ 400 USD each (or even cheapeer)
these cards spread on 3 or 4 mobos so you will need
3 or 4 mobo
3 or 4 PSU
3 or 4 RAM
you can run the system on usb linux, that costs next to nothing.

add the original 2 7970 (7770 becomes trivial in this setup)
you get 14 7970s, and each can hash at 700Mh/s (correct me if I am wrong)
that gives you 9.8G hash rate.

you have to work out your power cost, and where ever you put your rigs you have to make sure there is enough AMP for these rigs to run together.

so the only unpredictable factor is the difficulty level, with the current difficulty level you get approx 1BTC per day, till the next retarget date

It seems cards on PCIe 1x connection can't go below 625 in memory clock, or it's just me?
I can adjust the memory clock to as low as 150 on a card in regular 16x slot with multiple restart of MSI AB, but not the case for a card in 1x to 16x riser slot.

for LTC you need sufficient RAM to do the job.
and my advise is find a mobo, cheap but with as many PCIe as possible(pcie speed doesn't matter), coz you don't know how far you will go with the mining business, 

with my window open in the kitchen, my 7950s are mining at

68 C 3155RPM
65 C 2920RPM
61 C 2653RPM
73 C 3507RPM (a locked 7850, cann't undervolt)

Ok, lesson learned,
I did some google search this afternoon, and around 160w is common, but still impressive

after fixing the problem of MSI AB undervolt, I open the GPU-Z and monitor the sensors
it shows the VDDC is 1.028 avg (I set it in MSI at 1.063, below this value some of my cards will just crash sooner or later)
and VDDC Current is bouncing around 95A

So if I remember some high school physics correctly P=UI that gives approx 100w for each card, (I underclock the mem clock to 625 and over clock the core clock to 1000)

or should I use the 12V * VDDC Current In which gives around 115w,

if any of this is true, that's also impressive for a 7950, or did I miss anything?  my physics sucks so that's the best I can derive.

my personal experience for mining LTC, I can only run one 7850 + one 7950 with 2G of system ram, two 7950 with 3G of system ram
so my guess is 5G of ram to run three 7950 and one 7850 together

this compare to BTC mining, I saw lots of people use only 1G or 2G ram to run 5 or 6 cards......

if a card can't be undervolted the temp will goes up quickly and the fan noise........

also take into consideration of your system ram, it's called RAM intensive for a reason 

I should have googled and learned it

now all my 7950s are working at 1.063/1000/625 happily
and my only XFX 7850 seems has a locked voltage  , so now it's funny to see that it does less work but with the highest temp of 74C
other 7950s are all below 70C

I found it on ncix.ca don't know about ncix.com

but I was wrong about one thing, the promotion is not a reference 7970, it's a dual fan 7970 and looks nice.
http://www.ncix.com/products/?sku=70111&vpn=AX7970%203GBD5-2DHV3&manufacture=PowerColor&promoid=1323

I saw this option like million of times, but don't have knowledge what it does
I am going to try it now see if it works.

thanks crazyates

report back,
it works now and finally I can uninstall TRIXX and use only MSI AB