I believe the first 50 cent game was BH or HH

First 50 ¢ game shipped that way was Black Knight. ( BH was 3/4ths of a year later )

First 75¢ game was I believe Spiderman.

LTG : )

Family Guy from the factory was 50 cents. The latest code rev had a 75 cent default.

Concerning the early 50 cent game play pins, I agree with LTG.

* Black Knight (late 1980 / early 1981), probably the 1st shipped set @ $0.50/play,
but I believe some/many were adjusted by op's to be 25 cents per 3-ball game.
* Black Knight Ltd Ed., (mid 1981), 5 balls per game, $0.50 per play, 3 plays for a $1

* Black Hole (Gtb, late 1981), 2x25 cents / 1 play, or 1 SBA $ for 3 plays.
The BH sales flyer indicates "...and the first accepted at 50 cent play".

* Seems like Bally preferred to stick with 1 quarter for 1 play well into the 80's, but did drop down from 5 balls per game to 3 balls per game sometime during early/mid 80's.

* I see that Stern Lightning (Apr '81) and Split Second (Aug '81) both had
score/instr cards with: 1 play - 2 quarters.
Stern was transitioning around same time as most of the other manufs via going to: 3-balls (or 5) per game @ 1 quarter - 1 play; examples are: Catacomb & Viper (late 1981),
and 2 quarters per play for Orbitor 1 when it came out in 1982.

I can confirm that at least the limited edition Black Knight did new in box. Unboxed one back in the day.
But I know lots of places were charging $.50 or Two Tokens for Flight 2000 in my area when it came out, but I don't know if they shipped that way.

Further to waffles comment,
I see that there is one pic on ipbd for Flight 2000 (Stern, late 1980)
that shows a score/instr card indicating:
1 Play - Quarter
6 Plays - Dollar Coin

I can confirm BK came at 50¢ as I unboxed one before it came out.

LTG : )

It doesn't mean it came that way. With each game you got a big envelope with manual, and lots of price and instruction cards.

Picture on IPDB could be of any of many price cards.

LTG : )