Ive noticed many people toggling off mxp entirely because of shops, so now you can simply toggle off mxp for shops...
help mxpshops
"MXPSHOPS"
See also: mxpsettings mxpexits mxpitems mxpcompass
Usage: mxpshops
This toggles on and off mxp for shops. While it is on, players
under the level of 20 can query, buy, etc simply by clicking their
mouse. Players above can only buy.
Enjoy,
Splork