Mk3 vs Mk5 Buggy

I've started to mine jasmium and aluminum to get duraluminum and finally decided to make a buggy to collect these resources in mass and my question is if I should take the time to make a Mk5 buggy or would a Mk3 buggy with a Mk5 cutteray do the trick? Should I make certain parts Mk5 (treads, engine, etc) and keep other parts Mk3 (Chassis, hull, etc.) to keep the resource cost down ?

Worded differently, what the be trades off in using a Mk3 Vs Mk5 buggy?