Lapel Hole?Price?

They won't be able to do a good job at Jos a bank. You need to find a skilled tailor that can hand sew a button hole. My tailor charges 10 bucks for hand sewn button holes and would most likely charge more for a lapel w/ silk facing but he's cheap.

My tailor charges $20.

Ideally it should be a straight button-hole, not the key-hole shape used for functioning button-holes. It should also have a small loop of thread placed beneath it on the rear of the lapel, through which you place the stem of the boutonnière.

I commend you for trying to do things properly; there aren't many worse sights than a boutonnière that has just been pinned to the lapel because of the lack of functional button-hole.

You really should not create such a hole - evening dress is normally without.

Yeah, not sure what gave GBR that idea, a boutonniere is perfectly correct with evening wear.

Putting it in the pocket is certainly not acceptable, that is where your pocket-square goes, and I would probably avoid the services of any tailors who told you to do such a thing.

It can be rare to find an off the rack single breasted peak lapel tux with such a boutonniere
button hole, although you can certainly ask for one on MTM or bespoke. I've been to many weddings
where the flower is just pinned to the lapel however uncouth (or not) that may be.

I can never get the butoniere to fit through the hole nicely without causing some weird rippling in the lapel. I don't really care for it.