Great question, Zdeněk.
It’s worth differentiating between pre-funding and post-funding. Before funding, you don’t have a budget so you can’t hire either accept by using equity or leveraging existing, personal relationships.
After funding, one of your goals will be to surround yourself with the best people — pretty much by any means necessary. Coaching is more popular outside of London but it’s got a very high ROI.
I coach a number of startups in London — typically before and after Series A. To give you a rough idea, the way I structure my coaching engagements allows me to offer a month of coaching for the equivalent of 1 or 2 days of consulting.
Hope this helps.