The only other two subs I maintain are for JetBrains products and Office 365.
Not that I'm a fan of subscriptions, but in this case it's almost a no-brainer. Here we have a developer who cares about the Mac, who puts real effort into getting a quality program out, and yes, who asks to be paid for his work. Yes others are completely free, but from experience they also consume more system resources and are a PITA to remove. So not free, but so close as to make no real difference.
£14.99 with the 50% discount and VAT removal (being a company purchase) for 3 computers over 2 years - it works out at a few pence per month.
