What is the correct sizing here?

Forgot to say that I prefer to 4bet here instead of just shoving all-in like some players might do?
Reason is that BTN is a reg and he can think that i have fold EQ and he can shove something like AK.

So i should make my 4bet smaller? but then i give too good odds for calling.

Possibly a little too big in ordinary terms... anyone who just flat-calls you only has about 20% equity or less; so you need not worry about undercharging.

But the big raise does make it look like you want to be called less, perhaps prompting some to play QQ, AK here.

Raising too small is too obviously for value (I see some people minraise 4bet here and its a really dumb idea).

Anywhere from $8.50 or so to a shove I would say is completely fine.

With the fish in I like the bigger bet.

Would probably make it around $8-$9. Your initial goal for 4betting is that you want your opponents to make the most amount of mistakes and get calls from worse. If you size it to $13, they can find folds easier with worse. You also want to give some impression for your opponents that they have foldequity in case they want to shove with hands such as JJ/TT.

$9,99 is a good number, imo. U put a big price on, and still can make guys think u can possibly fold after this big raise.

We can go even bigger, if fish want to call, he will call bigger.

If so, the best is go all in already.

Not a mistake though...
There is enough money in the pot already

Sure, but I ll stick to my bet size instead of pushing.

You can do whatever you want, with collecting more info on vilains's preflop tendencies you can vary the size.
I prefer betting big when we have a fish in the pot.