Should I power up my 97 IV starmie?

I have this Starmie (or close mines 94 iv i think) and I haven't powered it up yet. Mostly cuz its a weaker version of Vapereon and he's so easy to get.

Do not power it up, use it both as a specialized gym trainer (if it has a low CP) or attacker (high CP). Thanks to its high DPS moveset and type advantage it performs relatively good against Zen Headbutt Snolax. But due to its low stamina it requires high dodging skill to be efficient

I wouldn't power it up even with the good moveset simply because you are probably going to have better use for your stardust. However, like R_canine said you should keep it for gym training,

+1 to what R_canine said. I have a 1227 Starmie with the same move set which can easily take out an 1800 Flareon as long as I dodge the charge moves, and a 2000 Flareon if I dodge its quick attacks too. (5 Water Guns, dodge, repeat; then Hydro Pump right after dodging a Fire Blast/Flamethrower.)
Boom, 800 prestige gained in ~15 seconds.