Going to 〇〇 is cheaper than I thought it would be. It will only cost about half of my monthly salary.
It's not nearly as expensive as I thought to go to 〇〇. It's about two weeks pay for me.
ーGoing to 〇〇 is cheaper than I thought it would be. It will only cost about half of my monthly salary.
「〇〇に行くのは思ったより安かった。私の月給の半分くらいしかかからない」
cheaper than ... で「…より安い」
to only cost about ... で「…くらいしかかからない」
ーIt's not nearly as expensive as I thought to go to 〇〇. It's about two weeks pay for me.
「〇〇に行くのは思ったほど全然高くない。私の二週間分の給料くらいだ」
not nearly で「とても〜ではない」
two weeks pay で「二週間分の給料」
ご参考まで！
Half of my monthly salary will be enough to travel there.
おっしゃられている内容は以下のようにも表現できると思いましたm(__)m
It will cost about half of my monthly salary.
「私の月給の半分くらいかかるだろう」
Half of my monthly salary will be enough to travel there.
「そこに旅行するのに月給の半分で十分だろう」
以上です。
少しでも参考になれば幸いです(*^_^*)
カナダ 
日本 
