～のは Noun ぐらいのものだ (〜no wa Noun gurai no mono da)
Explanation
Conveys that 'only (Noun) is the case' or 'nothing but (Noun)'.
Formation
Verb-casual + のは + Noun + ぐらいのものだ, い-Adjective + のは + Noun + ぐらいのものだ, etc.
Detailed Explanation
The ～のは Noun ぐらいのものだ pattern indicates that something is exclusively or solely that particular Noun, conveying the sense of 'That's the only thing...' or 'There's nothing but...' about a situation.
Examples
この小説を読むのは暇つぶしぐらいのものだ。
Kono shousetsu o yomu no wa hima tsubushi gurai no mono da.
Reading this novel is nothing but a way to kill time.
今日の夕食で良かったのはピザぐらいのものだ。
Kyou no yuushoku de yokatta no wa piza gurai no mono da.
About the only good thing at tonight's dinner was the pizza.
この映画を見るのは時間の無駄ぐらいのものだ。
Kono eiga o miru no wa jikan no muda gurai no mono da.
Watching this movie is nothing but a waste of time.
彼と話すのはストレスぐらいのものだ。
Kare to hanasu no wa sutoresu gurai no mono da.
Talking to him is nothing but stressful.
Grammar content sourced from hanabira.org.