に合わせて / に合った【にあわせて / にあった】

に合わせて means "to fit", "in time with": someone adjusts what they do so that it matches something else. It follows a noun and comes from あわせる合わせる, "to make match".

Before a noun, the form is に合わせた.

に合わせて or に合った

あわせる合わせる is transitive: someone does the adjusting. Its partner あう合う is intransitive: a thing simply fits. So に合った describes something that already suits, and it goes before a noun.

The same budget gives two sentences: one where you shape the plan to it, one where you find a hotel that already fits it.