Hi
I will write an script where User canb write product name, show price & they will navigate directly on Checkout page, as per attachment.
Let discuss more on chat.
I understand your requirements as you shown in the image.i would like to work with you and make the page as your convenience.
I am a beginner and very enthusiastic to do your work . I have sufficient knowledge on html and CSS .
Hope you like my work,Thank You :)