The bigger thing you should bump first is RAM. That usually gives the biggest speed boost to a system, especially if you're dealing with memory-intensive 3D work. Hard drive, you can always buy an external later for data storage.
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"You know how parents tell you everything's going to fine, but you know they're lying to make you feel better? Everything's going to be fine." - The Doctor
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"You know how parents tell you everything's going to fine, but you know they're lying to make you feel better? Everything's going to be fine." - The Doctor