"Quality" links, PBNs, guest posts, etc are just raw materials, it's how to use the elements together that improves rank. If you can find a service or freelancer to do so, then indeed you should pay for that effort, or else do the work yourself. As in:
1. If you don't have well selected keywords, that are relevant yet just moderately difficult, you're lost from the outset. Being the 500 millionth person to use niches like 'buy instagram likes' won't cut it. In bottom line KW Finder terms, stick to terms that have a difficulty level less than the low 40's pr so.
2. It might be helpful to start with an expired domain that has 1-2 high authority editorial links to it already in its history. Take that domain and add (in time) a few more such heavy duty links. Wherever you can, add a high editorial, 'brand name' type link or guest post to each PBN page that you can.
3. Per each keyword search through the first 50-100 rankings on Google, especially the first 20-30. Get as many comments or guest posts from them as you can, then move on to the next kw.. You might find 5-10 REAL quality links this way for the keyword, and that means for 10 of your keywords, 50-100 links. This is a simple and direct way to be checking your competition while doing this.
4. If adding Web 2.0 type properties, prefer the ones that are subpages that already have high metrics (striikingly, penzu, et al), not zero metric subdomains, to create contextual links from. Make 50-60 such subpage contextual posts (on tier I) pointing to the first keyword on your site, THEN (on tier II) 50-60 such posts pointing to EACH property post for that kw. Repeat for all other keywords you really care about. The effect of 50-100 T2 hi metric posts pointing to each T1 property post for that kw should be to rank most of those T1s in the top 50-100 for that kw. The impact of those 50-60 T1 posts ranking in the top 50-100, should be in turn to rank the pages on the main site for that kw even higher (page 1-2). Yes it's tedious to construct, but it's also tested.