PayPal extracts a hidden 3-4% margin on every USD invoice. Wise costs about 0.5%. For a freelancer earning $4K/month, that's €3,300 a year.

I hate QuickBooks. It's expensive, awkward, and completely overkill for my writing business. Unfortunately for me, it's also the most usable and affordable multi-currency, multi-account invoicing tool so I've had to use it for the last four years. Then I read Craig Mod's blog about building his own custom finance tool in a week.