Why pays someone when you can do it better yourself?
The genesis of the DIY Tour was based on:
1. The Rick Steves Athens City Walk: When visiting Greece back in 2014, I followed this detailed map. It covered a lot of ground for one day (we were booking!), but enabled us to see much of what Athens had to offer (Many tour books recommend that after you see the Acropolis you minimize your time in Athens, which may or may not be true). It then gave me the idea that this could be done for other cities.
2. Free walking tours I have taken in numerous European cities (almost every city has one: from Amsterdam to Zagreb). In almost every case you get a good sense of the city after taking a two hour free walking tour.
-Sandemans offers free tours in most cities. If you like what you see then you can sign up for a paid tour. This is what I did in Jerusalem: free walking tour of Old Jerusalem, followed by a paid tour of the Mount of Olives.
-Ironically Rick Steves isn't a fan of the free tours as he feels "you get what you pay for". To which for tours I agree (but not for most everything else), if you don't like the tour, then you don't have to pay. Also the only private tour I ever took took (a paid tour in Budapest) was quite disappointing (only made worse by then having to pay!).