Should I spend dust on this Cloyster ?

Offensively it seems to be as strong as a Lapras with same moveset, but the base stamina of Cloyster is 160 less, so it will die earlier (== less damage output per life). I don't know. Maybe, if you don't have Lapras.

Cloyster is a Ice type pokemon is effective against Dragon type pokemons. But spending of stardust on it , i have little or less knowledge. You can contact Nick whose Youtube channel Trainer Tips can help you.

if u r good in dodging , yes
if don't, noo

No offence, but I think Laraps is more wroth to power up, a ice type pokemon also.

Yeah, thats a great Cloyster, mine has the same moveset and I use it often against Dragonites, especially if there are a few and my Lapras faints

No way