I travel in Europe independently 3-4 times every year and often book private guides. Have had only good experiences, and sharing the cost with a couple of friends often makes it a good value as well. Because of a medical emergency I just cancelled an 11 day trip to Belgium and London I had planned for a friend and me. I always buy medical insurance (because a medical emergency could be ruinous) and never buy trip cancellation (because it's a fixed number and I'm willing to risk losing it and betting I won't.)
I just had a disappointing experience with ToursByLocals.
I booked an all day customized tour of World War I sites out of Ghent for Sept 22, for $774.49. Pricey, I thought, but the best option for making these sites doable for a friend with mobility challenges. I cancelled on Sept 9 because of a medical situation that would have made it foolhardy for me to take off to Europe. When I cancelled I was sent a polite letter with a link to their cancellation policy, which is clear: Cancel up to 15 days before the start date of the tour and get a full refund, including all fees.
I sent an equally polite reply requesting a little grace and a negotiation of some refund, considering I cancelled 13 days in advance on an expensive tour for a very legitimate medical reason. Their response: "...unfortunately we are unable to refund you and the Guide has not offered a partial refund as well...."
I am well aware that they are within their rights to follow the letter of the law, but still disappointed in them. And I do now have a $100 credit for a future tour, which I would happily mail to any of you asking nicely if I thought there was any chance it was transferrable. So caveat emptor!!