Are you really that limited?
What works for me for low/medium competitive search terms:
- 100 high PR society articles
- 10 BMR posts
- 50 web2.0's $5 fiverr gig (getting too annoyed with software to do myself)
- 100 AMR article backlinks for diversity
- 100 Scrapebox comments, I repeat this a couple of days
- 500 social bookmarks $5 fiverr gig
- 500 Wiki article backlinks $5 fiverr gig
- 10 Facebook fanpage comments
- Youtube video with channel commenting
- Couple docsharing sites
- 10-20 manual high PR3+ blogcomments
- Editing PR3+ wikispaces
- Tumblr reblogging with redirect setting to maindomain
Costs: $27,50 and about 3-4 hrs in total I think, and quite a bit of time scraping solid lists.
For easy/low competitive search terms (emd or innerpages):
- 5 BMR posts
- 50 High PR society articles
Costs: $6,- (assuming you have a BMR subscription)
Thats it, low/medium competitive keywords requires a bit more time and money but it's worth it.
Last thing I would like to add: If you don't want to spend money you shouldn't be in IM