If I had $7.5K to spend on two pins, I would buy a Whirlwind and Johnny Mnemonic. You'd probably be able to score both for $6.5K if you play your cards right.
Reason:
Whirlwind: classic layout, fairly easy to learn, has fun pinball moments, will appeal to everyone on your list,
Johnny: Fast, fast, fast. Fun modes. Has some interesting code depth and challenges spread across the throwing awards, modes, and glove matrix. Additionally, the matrix choices allow you to explore the game using completely different strategies. It also has some fun pinball moments, plays completely different than Whirlwind, and will probably remain a challenge to casual players.
