Just had my two year old Peugeot Boxer serviced at main dealer, they charged around £40 for a cabin filter, but as I was suspicious about some of the other items supposedly done, and charged for, I dismantled the dash (LS is much easier to change, thankfully), and took out a Denso filter, which was decidedly grubby, and dated 2012.
As you can imagine, I wasn't happy, and have since got compensation from the dealer, but the point of the story is, Denso is a good make, and is often fitted by the manufacturers as original equipment.
By the way, Eurocarparts will deliver that Denso filter to my door for nine quid, so not a bad mark up for the Pug dealer, even in the unlikely event of them paying retail.
Bandits, the lot of them!