high
The German word 'hoch' is used to describe something that is high or tall. It can be used as an adjective or an adverb. For example, 'Das Gebäude ist hoch.' (The building is high/tall). As an adverb, it can be used to describe a high level of something, for example, 'Der Preis ist hoch.' (The price is high).
The mountain is very high.
This sentence is describing the height of a physical object (a mountain) in relation to the observer. 'Sehr' means 'very', and here specifies the degree to which the mountain is 'hoch' or 'high'.
He jumps high.
This sentence is describing an action performed by a person. The person, 'er', is jumping or 'springt', and the adjective 'hoch' describes the level of the jump- 'high'.
The costs are too high.
In this context, 'hoch' is being used figuratively to describe the excessive amount of something abstract - 'the costs'. 'Zu' means 'too', expressing that the costs exceed an acceptable level.