The term "refurbished" essentially means that the unit is used, but the original manufacturer has done a basic system check on the unit and declared it "fully functional". They usually give a standard warranty (sometimes less time than new). (for example, Emotiva has 5 year warranty on new, but on used/refurbished/warehouse-seconds, they only give a 1 year warranty). So it will have to be up to you to decide if this "used" pricing is acceptable (just like buying it on the used market, but with a little bit of warranty insurance).
If it's on Amazon, be very careful on the details of the listing. I do see one Arcam UDP411 on Amazon, but underneath the title/pricing/availability, I see "Ships and sold by Sound Seller". In this situation, Sound Seller is just using Amazon as a marketing website. You will have to really verify if the actual seller is a certified Arcam dealer. Most of the time, the actual seller address/location is not even available on the Amazon website under the vendor details page.