IMO primo is best at higher doses like 700mg and above. Primo doesn't yield huge results. I'm running 400mg test c, 750mg mast e, 700mg primo and adding tren e at 600mg ew and dropping the eq out of the cycle. Mast is cheaper by far but it's not a "cutter". Mast is more of an aesthetics type aas and has no fat burning properties. People think it is a cutting drug because it's usually added in a cut type cycle. Realistically you can cut on any cycle. It all comes down to what and how you eat. You can cut on dbol and deca where most think of those compounds as bulking compounds. So to answer your question, its up to you which you'd prefer to run to cut. Primo is more expensive but will give you more results in strength and size than mast will.