It Is Called Price Fixing
Miele USA as the sole importer of Miele products keeps those allowed to sell Miele products on a VERY tight lead. Should said seller vary from the script, they will be dropped like a cheap date the next morning.
This is why you rarely (if ever) see Miele appliances marked down or on sale. It is also why you do not see many (if any) scratch and dented merchandise for sale. Unless the owner of the appliance (read consumer), themselves are selling the thing, or someone has managed to otherwise get their mitts on the damaged appliance.
Miele USA used to ship unsold appliances and such back to Germany, but that simply costs to much, so IIRC such appliances may now be offered to employees.
Persil laundry products fall under these rules, and that is why all retail sellers are pretty much within the same price range. Brick and motar stores sometimes sell the stuff at huge mark-up as do others, but they cannot sell below MieleUSA's "suggested" retail price.
What many online vendors do is offer incentives such as free shipping to bring the cost down.
Case in point for all this, just this week someone was selling Persil detergents and fabric softeners on fleaBay. Items were listed late at night, and were gone (taken down)by next morning.
There is a online retailer "GermanDeli" or some such that sells foods, housekeeping, housewares and so forth from Germany, and offers Persil as well. Do not think they get their product from MieleUSA though, but may have found away to work around the former's exclusive North American rights.
Oh yes, authorised Miele Canada and Mexico dealers are not allowed to send orders cross border. Vendors are not supposed to ship outside of their country.