I actually found a pretty incredible list of equipment, hyperlinked to subsections. It's not Rolemaster, and it doesn't list weapons or armor, but it covered 90% of the stuff I wanted, added a bunch I'll probably never use but it's there if I want it.
http://kimberlychapman.com/rpg/equipment.html
I'm copying the parts I want into my own spreadsheet, which I'll then be able to make a tab for each culture, set prices in their coin, and mark-out items not available there.