If the $5 dollar offer is no more from textbroker (hey, it was going to end sometime), there may be other ways to get the $5.00 or so to create the arbitrage effect. Spreading the exploitation around several sites, instead of relying on one site providing the bonus, would probably ensure sustaining the free lunch.
The simplest variation is to use various offer sites to generate the Paypal cash, then use the virtual CC function to set up the multiple textbroker accounts. Another way is to just use the pay for articles and blog review sites as a reimbursement tool for SEO-friendly niche articles one wanted to write in the first place.
So, join a bunch of pay-for-post type sites, but only accept the offers for articles that touch on niches you were going to write about, then spin the article for placement on your niche site and backlink articles. That way, even if the niche site you set up falls flat, you got paid for writing it anyway.