A new study of the UK book market finds that, outside the top of the bestseller list, Amazon really isn’t the cheapest way to buy.

According to this Guardian report by Alison Flood, the study (by Simon-Kucher and Partners) shows that “Amazon is only the cheapest option on its top 20 bestsellers, with books further down the chart costing 14% more than competitors.” Flood writes that the study:

analysed the prices of the top 100 print books in the UK between 30 October and 9 November, at Amazon and seven other online booksellers: WH Smith, Blackwell’s, Alibris, Kennys, BookFellas, the Amazon-owned AbeBooks and the Book Depository. While Amazon, which some consumers are considering boycotting over its (legal) tax avoidance, was the cheapest option for its top 20 bestsellers – 6% cheaper than competitors – for books ranked 21-50, Amazon charged a premium of 13% compared with the lowest-priced alternative, and for books in its top 51-100, that increased to 15%.

According to Kyle Poyar, a consultant at Simon-Kucher, “We found that Amazon was much more like a Tesco: supermarkets offer the staples, like eggs, milk and nappies, at a very competitive price, and make more of their money on the slower-moving products.”

It’s an interesting notion — though how the bottom third of the bestseller list can be considered “slower-moving products” isn’t obvious, nor does the Simon-Kucher study examine how the prices of non-bestsellers compare among the various UK online book retailers.