When making AI, I always try to remember not to over-complicate it, because it only needs to be viewed from the player's perspective. They often can't tell whether the AI makes a choice because it's clever, random or stupid. It's the same with a real opponent.
I might have lots of fun setting up a complex decision-making system based on needs analysis, 'thinking time', etc. Ok, I *will* have lots of fun doing that!
However, there may be a simpler way. For example, there may be a handful of different AI styles that could be simpler to program, then your game randomly chooses which style to use when assigning opponents.
The styles might be:
- Scrooge: the AI never spends big money on a tape (or anything), but instead tries to accumulate money without losing it.
- Ratings, ratings, ratings: the AI takes whatever action will get it the most ratings, in the short term. So, it might buy a great tape and then not have much money for a while.
- Steady as she goes: the AI buys mid-range tapes and has all settings to mid-range.
- Jackpot: the AI 'saves up' for one big move.
You could even give the AI a particular name when it is using a particular style of play, so the player can get used to the strategy over time just like with fighting real regular opponents. And players can talk about their success and strategies for particular combinations of AI opponents, which makes the game more enjoyable for certain players.
AI is usually the most fun for me when simple systems produce unexpected and complicated behaviours. In the case of this system, the player will be facing two AIs with one of a large number of combinations of styles, which can lead to a very wide variety of game experiences if everyone is competing over the same resources.
When designing styles of play, the idea is to make the AI always do the same simple behaviours, so your CODE (your effort) isn't complicated, but the GAMEPLAY (effect for the player) is.
I should probably terminate my waffle there. I tried not to make this a long reply, and just give the general principles, because I think that's what you're looking for. I hope this helps!