为此(wèi cǐ) - for this reason, to this end in Mandarin

为此 (wèi cǐ) points back at whatever was just said and marks what was done about it. It covers both English readings: because of this, and for this purpose. Which one you get is settled by the verb that follows.

It is written register. Reports, news items and formal letters use it freely; friends chatting use 所以 or 就 instead. The 此 gives it away, since that pronoun barely survives outside written Chinese.

The trap is the near neighbour 因此. 因此 states a consequence, so it wants a result clause: 因此价格上涨了. 为此 states a response, so it wants a deliberate action: 为此我们调整了价格. If a person decided to do something about it, 为此 is the right one.