I am new to bitcoin and wallet things, I try to buy something for US $4 (0.0000814) online, actually 3x times to try settle an online digital item order.
Nonsense.
$4 = 0.0093 BTC (that's 9.3 mBTC)
Not 0.0000814 BTC (0.0814 mBTC)
0.0000814 BTC is only $0.04
I had made several transfers but forever order payment never complete, and I didn't know why...
And you've given us absolutely no information to help you figure it out.
I am shock to the core to find out Electrum transaction fee
Then perhaps you should have posted this in the Electrum sub-forum. Now a moderator is going to have to move it there for you (unless you move it yourself).
after doing conversion.
0.1131 Bitcoin equals
48.81 US Dollar
Seriously?
Possibly, but probably not. Perhaps if you gave us something useful to investigate with we could help you figure it out. For example a transactionID or the address you were sending to and time that you were sending the transaction?
As already explained, you probably have your units mixed up.