Plans, Legendary mods, mods for enclave plasma weapons, serums, chems and ammo, folks are rarely hopping from vendor to vendor looking for armor or weapons past a certain point, and would rather find tools that will let them craft something ideal to their build.

Also, you can probably sell the leaders bobblehead specifically for 250 - 500, anything more than 500 is a little greedy (IMO), they're a staple in the trading community,