Thrift
Economy, Frugality
I promise this will be a really thrifty place because it's a thrift store! They wouldn't lie about that!
けんやく
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
いくらマイホームを買いたいからって、度を過ぎた倹約を強いるのはどうかと思います。
I don’t think it’s a good idea to force a higher amount of frugality on yourself just because you want to buy your own home.