I couldn't agree more with you.Private blog networks are great but they are pain in the a**. It;s just like running a separate business and while it is effective, it gets costly in the long run. Finding high quality metric domains, registering them, finding different C class ip's hosting providers, setting wordpress and writing content on it takes a lot of time and money. So if you can afford around $10,000 to $10 million dollars a year then probably go for it but my advice is to look for quality PBN providers. It's a hell lot cheaper, you get relevant and strong links and hey if Google closes them you just need to delete those links from your link profile and still keep your rankings. I have a network of more than 50 blogs and it's not easy to keep it running believe me it's my personal experience. I might start a service here so you can join that if you like.