Are you trying to say that Long Rifles (weapon of choice for the 10% or so who raid) should cost more than other weapons to upgrade?
If upgrade costs are based on level, there should be no differentiation between weapon type.
the other items should cost less than M107. Who is going to spend 500 fuel per lvl now to upgrade armors for less than 1% suppression resistance gain per lvl.
same with basically all other PVE stuff and the non godlike PVP stuff
500 fuel is probably worth about the same as 1 premium key and for 99% of unique items thats just way too expenisve to upgrade them.