This makes me curious, is that a high budget in comparison? (The show is obviously well produced so I assume it is a rather high budget, but what are shows that are in the same range in terms of costs?) 

Okay after a quick search I found out that Extraordinary Attorney Woo is definitely a very expensive drama and W 20 billion makes it into the top 20 highest production costs!

Here a few other things I found out:

 Mr. Sunshine had a production cost of ca. W 40 billion (1.67 billion per episode) and shows like Kingdom and Sweet Home having even higher production costs (per episode not all in all).  Arthdal Chronicles had the highest production cost with ca. W 54 billion.

Source: https://www.scmp.com/lifestyle/k-pop/k-drama/article/3138546/how-much-do-k-dramas-cost-make-budgets-keep-growing

Since Extraordinary Attorney Woo has 16 episodes the cost per episode would probably be around W 1.25 billion.

Comparable shows ( all have an estimated production cost of W 20 billion) are :

Hotel del Luna , Crash Landing on you, Vincenzo, Hellbound, River where the moon rises, Sisyphus, Criminal Minds, Memory of the Alhambra, Iris 1&2 each respectively, Saimdang Light's Diary, Athena: Godess of war and My country. 

Sources: https://en.wikipedia.org/wiki/Hotel_del_Luna https://www.tatlerasia.com/culture/entertainment/sg-most-expensive-korean-dramas https://www.kpopmap.com/top-7-korean-dramas-with-highest-production-cost/