its not about shipping cost or anything u mentioned above...
lets calculate the real cost here...
1 x RK-Box 450G = 1BTC (latest price)
assume we buy 3 RK-box (3BTC + 0.6BTC shipping)
now we need 3 RPI assume it 0.23BTC
and the last thing, we need 3 PSU assume it 0.47BTC
total : 4.3BTC
now we got 1.35 TH/s cost us around 4.3BTC
so, for this spec. 1BTC can get us 313GH/s (1350/4.3)
now we calculate the Antminer S2
1 x S2 1TH/s = 3.194 BTC (coupon)
for this S2, we dont need other accessories to run it
its all included
so, for this spec. 1BTC can get us 310GH/s (1000/3.225)
Conclusion :
RK-box - for mid player in mining, if ur wallet is not big enuf
S2 - only for big wallet
your math is not correct. for lots of us.
A) rasp pi don't need it why I have a pc that has my mining covered cost = 0
B) psu's hmm at least 5 off line psu's maybe 6 some are 1300 watt golds and some are 1000 watt plat's cost = 0
c) 3 rk-boxes = 3 btc or just under 1800 usd hash at 1350 gh
so spend 1800 usd and get 1350 hash vs spend 2200 and get 1th
many miners are mulling exactly the above and not your figures.
GRANTED SOME MAY BE DOING YOUR IDEA of the costbut i know many are doing what I just printed.
I also like that an entire rk box dies I still have 900th of hash.
my s-2 dies I have 0 hash.
I may buy 1 rk box per week and spread my cost out slowing increasing the hash . depends on how they run.
THEY MUST RUN AS GOOD AS AN S-1
I figure S-1's are better then 95% good closer to 97-98% . if the rk-box is that reliable it will sell like mad.
shipping?
if we're going to calculate the real cost, then you should add the rpi, why?
assume u dont have pc
u still can get S2 running, rkbox?
what i mean is, S2 is controller included, while rkbox "NO"
and PSU... if u're talking bout PSU, lets use "AntMiner S2 1TH/s Kit", its without PSU and case (we can run S2 kit without case; same with rkbox, but i got bunch of pc cases like garbage, so cost = 0)
which is cost around 1667 usd (2.978 BTC)
and RK box? shipping included, its around 2100 usd (3.75 BTC), and... still without controller
its not like am telling u not to buy this RK-box, its pretty awesome, better than S1 for SURE!
but, i just want you to know, "if you want to compare, dont forget to compare all the parts"
for example: well i can say that S2 kit cost me only $1000, why? I have a small GPU farm that has my $600 covered cost = 0 << this is not good for comparing right?
$1667 for 1THs or $2100 for 1.35THs (still have to buy controllers)
maybe for 1.35THs it'll be around $2230 (with controllers included)
and, still the conclusion :
RK-box - for mid player in mining, if ur wallet is not big enuf
S2 - only for big wallet
like you said, "may buy 1 rk box per week and spread my cost out slowing increasing the hash", yes! agree with this, we can slowly increase our hashrate <