You pay for the BOHF's (Score 1)

"BOHFs (Bunches of Helpful Fixes) are occasional updates to SOT Office. To install a BOHF you will need an installation key, which can be obtained by signing up for the SOT Office Annual Maintenance program. We strongly recommend you update SOT Office to the latest available version before using it for the first time."

cost for the SOT Office Annual Maintenance program: 80.74 USD including TAX 22%