Is there a logical reason to buy bitcoin for more than it costs to mine it? For the sake of this question let's assume bitcoin was useful and had value beyond speculation.

Why would you ever buy bitcoin above mining price?

I have heard various estimates of what it costs to mine a bitcoin. 

One answer on the topic on quoara suggests the electricity costs around 400$ (this is from late August 2017).


  Source:
  https://www.quora.com/How-much-does-it-cost-to-mine-1-Bitcoin-in-the-US


Let's say with equipment investment and increased difficulty it now costs 1000$ or even 2000$ to mine a bitcoin.

Given that it is relatively cheap to mine bitcoin and there are even managed server solutions you can rent, is there any logical reason to buy bitcoins at a higher price, than they cost in production? Why are people mortgaging their houses in order to buy bitcoin at 17.000$ per coin when they could simply buy computers and electricity and pay only a fraction per coin?

Shouldn't the price of bitcoin be very closely tied to the price of producing bitcoin?
Mining:
It's a lot of trouble and expensive to set up a proper rig and the return on investment can take a long time when mining. It's not as cheap or profitable to mine the coins as you make it seem.

This online calculator:

https://www.cryptocompare.com/mining/calculator/btc?HashingPower=12&amp;HashingUnit=TH%2Fs&amp;PowerConsumption=1300&amp;CostPerkWh=0.15

allows you to enter electricity cost, energy consumption and hashing power of specific rigs to figure out how much you'd make. It takes into account total network hashing power, average block time etc.

For example:

An antminer S9 (currently viewed as being the best pro-sumer miner on the market) has a hashing power between 12 and 14 TH/s and consumes between 1200 and 1400 Watts of power. at an average electricity price in the US of $0.12 per kW/h (and Europe's avg price is between 12 and 18 cents) you can expect to profit just a little under $500 per month on the machine.

Those machines are sold out direct from the manufacturer but you can find them from resellers on amazon or eBay for between $5000 and $7000 depending which batch they were from. It would take you a year to make your money back on your investment, and since the nature of that playing field is that a piece of equipment's yields reduce over time it will most likely take a lot more than one year to break even from the purchase of that miner.

Most miners are pretty much the same or take even longer to pay back; feel free to play around with that calculator and input different mining rigs you find on the internet.

Renting Servers: this site, the top result in a google search,
https://www.nicehash.com/buy will rent you 50TH/s of hashing power, for 24 hours, for ~$94USD (they charge in Bitcoin). Using the calculator I linked above 50TH/s and an electricity cost of $0 would yield $2447/month worth of bitcoin or just over $81/day. So you'd be giving them $94 for $81 worth of Bitcoin.

Bottom Line: the reason people don't easily mine it for a tenth of the cost is because it's neither easy nor much cheaper to mine it.