Some of the mining contracts on Ebay are obscene. Some people are paying the equivalent of $50 for a weekly contract that only returns about $2.5 worth of BTC.
I was glancing though one mining services provider: Bit-Mining.co (
https://bitcointalksearch.org/topic/ann-bit-miningco-btc-ltc-mining-services-351935). Their Platinum Pack promises 20GH/s for 1.06 BTC (with today's prices roughly 716,35 €). They provide a 4 years warranty for the hardware, but they do not state clearly whether the payment is for the whole period (4 years) or just one single year. If it means an annual payment of 1,06 BTC, it'd be 27,03% of the expected annual income. On top of that, of course, their 8% fee from the 1st year.
This is where I stop following, though... How come there can be percentual fee from the first year, if there are no income realized before the whole block has been solved?The block time according to Bitcoin Mining Calculator (
http://bitcoin.web-share.nl/), which takes into account the current difficulty level (908350862.43702 : 1), gives an estimate of 6 years, 2 months, 5 days, 10 hours, 13 minutes, 16 seconds/block. This equals to 3,923 BTC estimated cumulative profit annually. Numerous other mining calculators give similiar results (
http://www.bitcoinx.com/profit/; http://tpbitcalc.appspot.com/ etc.). In order to "
redeem the prize", one has to manage to solve the entire block, right? I mean, there are no are no 34% or 90% ready blocks etc. Please correct me if I'm wrong...
It made my alarm bells to ring when I read that this one peculiar mining services provider, Minerlease.com (
http://www.minerlease.com/contracts/half/) is advertising mining contracts that promise "30 BTC return for
1 YEAR CONTRACT (25 GH/s)". Sounds too good to be true, huh? Especially when you take into account that the estimated block time for 25 GH/s is around 4 years, 11 months, 1 week, 3 days, 10 hours, 16 minutes, 34 seconds/block. ... oh, and the contract is set to begin in April 2014, the time by which the difficulty level sure has gone drastically up from the current one (indeed, yesterday the difficulty level was still at 707408283.0515 : 1; today it reached already 908350862.43702 : 1). Their charge is 500 US dollars.
Anyway, I sent them an inquiry conserning this major disporoportion between their estimates and the ones that numerous calculators provide. Suprise, suprise... for a week now, no answer. As far as I am concerned, this peculiar service provider,
Minerlease.com seems highly untrustworthy to me.
However, I have some serious concerns. For example, pretty much none of the companies offering mining contracts are actually mining yet, so there's no guarantee that these "mining companies" aren't just some random fat kid in Australia soliciting unguaranteed funds.
Hehe, I thought of the exact same thing. However, I'd be more concerned that the fat kid is actually slovakian though... xD Anyway, even if this fat kid would be doing his mining job conscientiously, as a highly unregulated business, how can you make sure that he doesn't just keep the prize to himself and use you solely to pay for his hardware equipment?
At the moment, I am looking into this provider that is selling stocks from each set of hardware it purchases. You can see some of them here:
http://www.bit-miner.com/?page=pricing. They offer certain assets where you can buy shares from. E.g. 650 GH/s divided into 5000 shares; you will be granted with GH/s per share, according which you get paid to. What's suspicious again, though, is that they don't even report their share prices, which actually makes any further calculations impossible! They don't have any shares at the moment, but will have some new in the next few days (I emailed them).
However, I wouldn't trust this one either: prices are all obsecure and there is no guarantees that if they ever make any profits, they won't just hold those to themselves instead of sharing those among the stock holders (who are actually not stock holders, but who buy a right to the dividends)...