It is a cheaper way to boost. Boosts are available battle.net wide. I picked up a number of boosts at the recent holiday sale, so this worked as recently as late Dec 2018.
The process is fairly simple
- Create Starter Account
- Buy BFA and select the starter account
- Do NOT add game time or sub
- Delete Starter Account with an automated ticket ( https://battle.net/support/help/prod...1/878/solution )
If for whatever reason you accidentally add game time or sub, GMs can remove the accounts with a regular ticket, but you likely will have more hassle/time involved.