...Without paying thousands
Most importantly, it does these really economically because there is now a very liquid market with aggressive competition among suppliers of these features.
We don't think that this is confined to trade publishers, either. Academics also have unique challenges, which is why they end up fulfilling journal and book orders through Metapress and the like. However, it is technically very easy to upload digital journals and their individual articles for sale on Shopify, and hand out discount codes, provide bundles and upselling promotions, and so on.
Shopify costs about £30 a month. There is a rich ecosystem of additional apps -- such as basket abandonment protector -- and the others you can see here, which tend to be anything between free and around $19 a month. And Bibliocloud's Shopify integration ships as part of the standard user license: no extra charges.
In other words, you can have a state of the art, revenue-generating, modern, beautifully-designed website for a tiny amount of money.