However you need to be more of a generalist with experience in many different sectors if you wish to be effective at taking over existing businesses, mainly because many people will be trying to scam you or overcharge you during the buying stage - you must make sure you are paying the right price, based on accurate info
This is like the insurance agents that are naming themselves as financial advisor. But in literacy, they're good with the product that they're selling but they're not entirely educated in finance just because they're selling a financial product. I might have a different approach to this one. Building from scratch is going to literally take time, experience, hardships, heartbreaks, upsets, and all of that usual thing for starting out with their businesses and they're normal. If I have the money, I'll find someone who's really experienced and has been in the business industry for how many years and will ask some tips to avoid the usual norms of mistakes come to me so, basically I'd start with scratch but if I think that I can't tolerate the heat, I might just get a leap of faith into buying existing business.