だけ（のことは）あるLives up to expectations
だけ（のことは）ある acknowledges that a good result or quality lives up to an expectation created by effort, experience, cost, reputation, or preparation. It often corresponds to “it was worth it,” “no wonder,” or “as good as expected,” depending on context.
Expectation and result
The clause before the pattern supplies the reason for expecting something good. The surrounding sentence then identifies the favorable result that justifies that expectation. This is usually praise or appreciative acknowledgment, not a neutral statement that two facts happen to be connected.
What creates the expectation
Effort, reputation, and cost are especially common bases for this evaluation.
発音が見違えるほど自然になった。毎日練習を続けただけのことはある。
Her pronunciation has become remarkably natural. All that daily practice really paid off.
AnalyzeThe improvement is presented as a result worthy of the sustained effort.
老舗として名高いだけある。料理だけでなく、接客も行き届いている。
It lives up to its reputation as a long-established restaurant. Both the food and the service are excellent.
AnalyzeIts reputation creates the expectation, and the food and service justify it.
値段が高いだけのことはある。この椅子は長時間座っても疲れにくい。
This chair lives up to its high price: it remains comfortable even after sitting for a long time.
AnalyzeThe quality is judged good enough to justify the cost.
Acknowledging a result versus giving a reason
だけ（のことは）ある directly acknowledges that the result lives up to the expectation. By contrast, だけあって foregrounds the preceding fact as the reason that the following result is unsurprising.
彼は十年現場で働いてきただけあって、判断が速い。
Given that he has worked in the field for ten years, it is no surprise that he makes decisions quickly.
AnalyzeHere the experience is explicitly presented as the reason for the quick judgment.
More examples
発表は内容も構成もよく練られている。半年かけて準備しただけある。
The presentation is thoroughly polished in both content and structure. The six months of preparation clearly paid off.
Analyze何度も試作を重ねただけのことはある。このソースは味に深みがある。
All those test batches were worth it. This sauce has real depth of flavor.
Analyze一流の職人が仕上げただけある。細部まで丁寧に作られている。
It shows the work of a first-rate craftsperson. Even the smallest details are carefully finished.
Analyze予約がなかなか取れないだけのことはある。この旅館は景色も料理も素晴らしい。
This inn deserves to be so hard to book. Both the views and the food are outstanding.
Analyze十年この仕事をしてきただけある。難しい質問にも落ち着いて答えていた。
His ten years of experience showed. He answered even the difficult questions calmly.
Analyzeこのコートは値段が高いだけのことはある。生地が丈夫で、形も崩れにくい。
This coat lives up to its high price. The fabric is durable, and it holds its shape well.
Analyze