「〜してまでする必要はない」は英語で次のように言えます。
ーYou don't have to go to that length.
ですが、この場合は次のように言うと自然で良いでしょう。
ーYou don't have to give her such an expensive present just to please her.
「彼女の機嫌を取るためにだけに、高価なプレゼントをあげる必要はない」=「高価なプレゼントをしてまで彼女の機嫌を取る必要はない」
ご参考まで!
You don't need to buy expensive gifts just to keep her happy.
There's no need to go as far as giving expensive presents to keep please her.
ご質問ありがとうございます。
・「You don't need to buy expensive gifts just to keep her happy.」
「There's no need to go as far as giving expensive presents to keep please her.」
(意味) 高価なプレゼントをしてまで彼女の機嫌を取る必要は無い
<例文>There's no need to go as far as giving expensive presents to keep please her. Don't waste your money.
<訳>高価なプレゼントをしてまで彼女の機嫌を取る必要は無い。お金の無駄遣いしないで。
参考になれば幸いです。