You could not be up $150 your way because you didn't have a full BTC. You could only purchase what you saved on electricity which is $10 by not mining and using the savings to purchase with.
If I had $10 (what I saved by not mining) and purchased BTC (assuming no fees) I would be able to purchase 10/500 of 1 BTC or 0.02 btc
in that same time frame mentioned above now when sold at $650 per BTC I'd have 0.02 * $650 or $13 dollars profit before paying fees from investing savings from not mining.
Would you rather have a profit of $13 minus fees
or
$150 minus cost of $10 (electric cost) for $140 profit?
I'd rather have $140 then $13 so it CAN MAKE SENSE TO MINE AT A LOSS!
Not really sure what's so hard to grasp about this?
You're not making any sense, we were talking about mining at a loss, i.e. where the cost of electricity is higher than the value of the coins you are mining. If you can mine 1 BTC for $10 of electricity, you're not mining at a loss!
I assumed what you meant was that you mined 1 BTC at a net cost of $10, i.e. that you paid $510 in electricity to receive 1 BTC of value $500, which is what mining at a loss is.