Cannot purchase, please fix

I really enjoy the concept but I do think its a bit pricey considering I have no hard copy. But main concern is I am unable to purchase and it constantly says it is because the content is being modified..
Please fix.

On another note offering packages of comics for a cheaper rate would be cool. (3 comics of 2.78$ for 5.99$, for example)

Thanks and keep it going.

John Doors about Simpsons Store, v5.0.1348