It was fixed-price contract to develop Python scraper to scrape 2 websites.

I always charge ~$200 per website. We agreed $200 per website. I agreed $200 blindly without analyzing those websites because I was busy in other things.

Usually it takes a full day or upto 3 days to write and test code to entirely scrape a website.

Today, I studied those 2 websites in question and found a trick to scrape entire website using a single link, in short it will take me max 30 minutes to write scraper for both websites.

Should I still charge my client $400 in total? Or tell him that I figured a loop-hole that make it easy for me.