How long to farm from shard shop

Hi

Say if I devote all current shipments and character farming to shard shop currency how long would it take to unlock a 3/4* toon from there and also then to 7* it?
So if I devote all cantina store GW store guild store fleet stores to it, then all cantina farming (assumin two refreshes would net me say 12-15 shards at a 8 energy node).

Thanks!