高い
たかい · takai · JLPT N5 · i-adj
expensive
🗼💰 Sounds like 'a tower-kai': taka = high, so a tall tower and a high price
The kanji 高 began as a drawing of a tall watchtower, so height is its core sense. Japanese uses the same word for a high price, just as English says prices are high. Taka also appears in the surname Takahashi, high bridge.
高 — pictograph of a tall building/tower
高 is a pictograph of a tall structure, likely a watchtower or multi-story gate, with a roof on top, an upper chamber, and a base below. From this concrete image of height it extended to the general meanings 'tall,' 'high,' and figuratively 'lofty' or 'noble.'