Between profile links and article marketing, it sounds like you'll be building a pretty low quality link profile - one that could be susceptible to penalty.
If your client has a very limited budget, I'd suggest that they write and provide you quality content that you can use to gain some higher quality backlinks (i.e. guest blogs, etc.).
Perhaps they could also get links from partners, vendors, etc.
I'm not saying you shouldn'tpick up a few links from user profiles on established sites, but I would keep that a small portion of your link building efforts.
