the 2 minute transaction with onlye 1,21 fee:
https://blockchain.info/tx/ac844ab47191015296c3e32daede903dcaff772e145973c6a197efae1e1de5c0
For the tx you gave, the fees in sats/byte was 265, not super low, nor high, it was in the probability of getting mined in 3-15 blocks.
There are certain miners who do not choose transactions, they merely include transactions as they come randomly.
Most big miners do have a transaction piority system whereby their own txes and high fees txes have piority.
Winning the jackpot once or a few times means nothing in terms of probability, doesnt mean you will win forever and always.
Transaction fees is based on sized of transaction which depends on number of inputs, if you keep receiving inputs from small amounts, when you try to send a big transaction, this is what we call a dust transaction, your transaction size would be huge because of too many inputs. For the last time , no such thing as always giving the same amount of fees.
Or to use an example you like so much, assume that you are paying for a 1 million usd house, the seller of the house will increase fees based on number of notes you use with each note increasing your fees by 2%.
If you pay with a fictional 1 million dollar note, you only pay 2% of that 1 million in fees as only 1 note.
If you pay with 2 dollar notes, your total fees might be higher than the price of the house.
I recommend you using electrum wallet and enabling the dynamic fees feature. It automatically calculates your transaction size and gives you a small slider. Once again, no such thing as a static fee, optimal fees all depends on transaction sizes which in turn depends on number of inputs to the transaction. Assuming you know the size of your transaction, consult https://bitcoinfees.21.co for the optimal fee in sats/ byte and calculate from there, or simply using the electrum dynamics fees calculation feature.
Not sure what you mean on money being gone. For the last time try not to see cryptos in fiat... Even in a double spend, assuming it was made by you, only one or the other would get confirmed ultimately, how is the bitcoins lost? In a double spent, you use the same inputs for two transactions, nothing is lost even if only 1 confirms, it is usually not possible to do a double spend accidentally from common desktop wallets anyways.