@Bum , Correct me if I am wrong but you are missing the multiplier in your "Max loss" calculation since the loss will be per stock (underlying) and not per option contract right ?
1 option contract = 100 stock
If Stock price is below 50, then $5 has to be given per stock i.e. 5 * $100 = $500
We have to subtract the option premium we got, i.e. 1.30 - 0.70 = 0.60
Therefore, net loss is $500 - $0.60 = $499.40
Please let me know if you agree.
And no, I am not a super experienced options trader.