In Catan, a development card costs one sheep, one wheat, and one ore, three resources in all. Here are development cards that you might be able to get for those three resources:
- Year of plenty. Two resources of your choice. This is a 3- for -2 trade, but you get two "scarce" resources for three that are (presumably) abundant. If you are playing an ore-wheat-sheep game, you are probably short of brick, and/or wood. This may be close to a "breakeven" trade.
- Two roads. Two brick and two wood. Four resources for three. Plus the fact that brick and/or wood is likely to be scarce resources for you as discussed above.
- Monopoly. Depending on when and how it is played, it can be an "explosive" card, both for helping your own development, and hindering all of your opponents.' Arguably the best card in the deck.
- Victory point. Establishes a "basic" trade ratio of three resources for one victory point.
- Largest army. Requires at least three knights, sometimes four or more. Let's say an average of four. Then you need 12 resources to get two victory points. That works out to six resources per victory point. The difference between knights and the above is that in addition to getting you two victory points, the four knights save you resources (and hurt opponents' production) by moving the robber away from you. These can be valuable if relatively few sevens are rolled in the game.
Are there experts (tournament players or at least bloggers/you tubers) who have created tables analogous to mine that can be used for a "check?" How do these tables differ from the above? Have I missed or overlooked anything?