To add to this thread another thing to take into consideration is the different courier companies have different depots in different areas.
Some have more main centers and that charge is lower than a regional charge.
@BumbleBee is correct in saying that packaging and pricing tiers are taken...
I am not going to vote as I know the pros and cons of each courier company having come from the courier industry. Historically the majority of vape shops & online stores use TCG therefore the ‘vape clients’ know the service.
Each courier company offers different things applicable to your needs...