Here is an idea for the Market Wards that I feel is a good compromise for a lot of people...
Sure, some will hate it....
C'est la vie!!!!

ok... You do your item search for "Item X"
It is available...

You can purchase it directly from the counter and it goes into your retainers inventory

or

You can purchase it the old way by going to the correct retainer and getting it yourself
In which case it goes into your inventory, like normal

That way, if you are buying multiple items, you can do it all from the counter and then just retrieve it from your retainer
Think of it like sending your retainer to go pick up your supplies... makes sense within the context of what a retainer is. Less running for players but keeps the hands on approach of having actual retainers selling stuff

If you like to go physically browse retainers, then by all means you most certainly can