But how would it help win? It can't be used in PVP. And for repairs, we already have the option to use kits at any time (which are cheaper than merchant repairs anyway). All this would do is give the option to pay a little more for repairs, with the convenience of having access wherever you are, and without the hassle of buying repair kits all the time and clicking each armor piece one-by-one.
Just keep repair kits in your bank and use the banker when you need to repair.
That's what I do, and it works like a charm. Across all charaters, too..