I don't think this is the kind of website where I "help someone to use it". Instead of speaking in the abstract I may as well show you so you can see what I mean:
As you can see, the whole point of it is designed around quickly glancing at prices. And I don't think it makes sense to tell people other places they can find prices if they can't see well enough to use this website.
It's been a while since I looked at things like this but have you done simple stuff like check whether the colour contrast ratio [0] meets WCAG standards?
What about making the orange highlight work when tabbing through the website with the keyboard?
What about having a Skip Navigation / Skip to Content link? [1]
Thanks for the link about "skipnav" I haven't heard that term before. I don't really see how that can fit in, though? I guess the category links right at the top of the page is the closest concept?
It doesn't make sense to skip down to item number 200 since there's no way to know what's down there. Best to look at items 1-199 first. That is the same for all users.