DL: https://www.dlsite.com/maniax/work/=/product_id/RJ219694.html
No text: 64-123
Extra: 124-365

Start with 128, I found out the size of these images could be tiny but still have the same quality; I opened it in Microsoft photo and saved as new, the sizes directly go down from 21MB to 13MB. Then, I downloaded some software which allows me to batch resize multiple images, and I typed exactly the same picture resolution, the sizes became to 5MB.
I dont know much about pictures, but Really？

@wcchaa
Don't do that! Everytime you resave the image you lose quality and add more noise to the pictures.

Base +7

@Crummydoll
I wish I dont need to do that, but the sizes are bigger than the upload limit 20MB.

Base +6