A conditional phrase meaning "if only (one) has..." or "as long as (one) has..." indicating that a single necessary condition is sufficient.
お金さえあれば、世界中を旅行したい。
If only I had money, I'd like to travel around the world.
連絡手段さえあれば、遠くにいても安心だ。
As long as there's a way to contact each other, it's okay even when we're far apart.
時間さえあれば、手伝いに行くよ。
If I only had the time, I'd go help you.
材料さえあれば、簡単に作れます。
As long as you have the ingredients/materials, you can make it easily.