What Should I Do With This PBN?

I'll admit, this is sort of a strange problem to have.

I've come into possession of some pretty strong domains, and have access to acquire many more on the cheap. All of these sites have contextual dofollow backlinks from PR8/9 sites like CNN.com, HuffPo, NYT, etc. I've already begun building out these domains with original content on separate hosting accounts and variable CMSes like you would for a PBN.

I don't really have any money sites to point them to, though. I've created a few niche Adsense sites, with the intention to power them with my PBN, but my understanding is that fresh sites like this take months to rank these days.

Here are my options as far as I can tell:

1. Continue building out new niche sites and wait 3+ months for them to start generating revenue. - This option is probably most profitable in the long term, but delays gratification.

2. Buy some established niche sites on Flippa (or some place) and boost them with my PBN right away. - This could also be very profitable long term, with less of a wait, but requires more up front costs and carries the risk of dealing with scammers.

3. Just sell the sites. - Trivial upfront cost and fast money, but probably selling myself short and getting less value. Higher risk of getting scammed.

4. Sell SEO services - Profitable, possibly recurring revenue, but requires some marketing skill and knowledge. Hard to determine upfront costs.

Option #4 currently intrigues me the most, and if anyone has any advice or experience to share, I'd love to hear it. I considered launching a WSO and offering contextual links for a small monthly fee. But I see that it's mostly info products being sold there these days. I'm also concerned about failing to write amazing copy, falling off page 1, and burning a bunch of money bumping threads. I haven't yet explored other marketplaces.

I'm very reluctant about options 2 and 3. I acquired all these domains after the last PR update, so while they have great PA/DA/CF/TF/etc and solid backlink profiles, none of them have any PR or revenue, which I think are typically the big selling points. Then again, people do seem to be spending a lot at GoDaddy auctions for crappier domains than mine, so who knows. I guess my main concern is getting scammed, because I've never bought or sold domains and it seems very risky.

If I can't figure out a reasonable gameplan, I'll just go with option #1 and wait it out. Making some money right now would be nice, I could use it to be honest, but I have a day job and my life doesn't depend on it.

Sorry if this is very long. Thanks in advance.