I'd say make SA free
Then set up TOL like SA is now new account with 30 days game time or just the upgrade
HS can still be optional
I agree, let returning players get SA when they reactivate, that will alow them to use Imbuing, reforging and new loot and go to Abyss = much better chance, that they will stay.
Make a Return to Britain offer = 30 days gametime, SA upgrade, ToL and HS to same price as a new SA account cost now.
For new players, if they start to pay for their trial account, it will be upgraded to SA and they can play most of the game.
If they choose to but the game, give them a start pack, 30 days, SA, ToL and SH = price of that they pay for SA today.
Maybe make it so it is the same code, you can use to start a new account with 30 days and uptodate packs or restart an old account with 30 days and uptodate packs.
Make it easier for new and returning players.