IMPORTED MAGS: THE DIFFERENCE IN PRICE

There doesn't seem to be any correlation in the original cover price of imported magazines in Thailand versus the price they're sold for.
Take two examples from the food magazine sector, both from the U.K. Olive magazine has a cover price of £3.40 and is sold here for 295 baht - the equivalent of £5.20. However Jamie magazine, which has a cover price of £3.99 is selling for 475 baht - or the equivalent of £8.40. Both magazine are roughly the same weight.
I appreciate the costs for shipping, etc, mean imported magazine are necessarily more expensive here, however I cannot understand why there is such a difference (180 baht) between these two magazines.