What are you trying to sell? A web template or the Invoice template?
The site is very basic, just a few sections with image links and text.
The invoices, while clear, are also pretty simple and maybe even a little outdated looking. Plus the largest size only having room for 4 items isn’t very efficient. The header and footer can be condensed a lot more to show a better hierarchy and space for the most important part, the items and costs.