I'm seeing some cases of tag spaghetti. Why might we need all of costs, price, and fares as separate concepts? costs is one of the synonyms of our old budget tag along with cheap, deals, shoestring, discounts, and no-costs. This set of tags is explained as: Questions about minimizing cost...

How about unifying them all into a single tag: fares-and-prices (alternative suggestions welcome), which covers all usages of fares, prices and costs. We'll remove costs synonym to budget and make it a synonym to the new tag instead.

As far as consistency goes, you are right -- we need to agree on a policy and follow it through. I'm not convinced by your argument that all language-related questions should be tagged languges -- I mostly agree with Andrew Grimm's answer to the question you linked to. It's similar to countries...