Here's an idea that could work as a compromise to both warring sides here. The only caveat is that it would require a delivery system to be implemented first.
So let's assume they do decide to put a market window just outside the wards. At this window, which acts as the item search counter, you can do all the searching you can already do today, with improvements as SE implements them. After you search for the item you want, you can choose to leave the search counter and go find the retainer selling the item, as normal. Or, for a small fee based on purchase price (as mentioned above) you can 'purchase' an instant-buy service from the NPC at the search counter. Without bothering you to go find the NPC yourself, they will send a liaison into the wards on your behalf to find the specified retainer, purchase the item for you, and send it through the currently unimplemented delivery system. All you have to do then is go to wherever you pick up your mail (probably one of your retainers) and get your item(s).
The net effect is this. Those who don't mind going into the wards and doing their shopping can do so normally without incurring a fee and being able to instantly have their purchased items in their inventory upon purchase. Those who are inconvenienced by entering the wards can have their instant-buy service, and all it will cost them is a small fee and the time it takes to gather their purchases from the delivery system. Having those detriments to the instant-buy feature would still give the edge to going into the wards yourself, but not so much that the instant-buy is more of an inconvenience to those who want it than simply entering the wards.
Thoughts? Flames?