Originally Posted by TheSquealer

Define "high trust"
Put a value on "high trust" per each link.
How will you identify "high trust" exactly and calculate your ROI on that investment?
What is the formula you will follow to identify links worth buying?

The obvious answer is that you can't. At best it will be a guess and without a lot of experience at watching linking + SERPs and moving up and down for phrases you target, it will be a horrible guess.

How do you make sure you get the most bang for your buck or that its even worth it when you are betting on ill defined and ambiguous concepts that have no clear, easily defined value?

There are very few high PR adult sites selling links that are worth buying.

I can't recall since i haven't personally bought links since 2008/9 and i am mixing so many deals up in my head between what I sold and what I bought. But a site like naughty.com as an example, would sell links as you can see in the sidebar, they appear to still be selling links and its going to cost you much more than 200.00 a month and give you a tiny bit of traffic.

The benefit from that, assuming your site/network and everything is perfectly optimized will be minimal. This is why itraffic guy is saying you are much better off just building your own link network. Something you own forever that will never go away. Something you control. Something that over time, continues to increase in value to your sites that you are linking to.

Build.
Build slow.
Build big.

Or... when it comes to investing your time and money, stick to what you control and stick to what you know.