I disagree whataworld, at least some RRSP assets will be advisable even at the $30,000 income level for a couple of reasons

Qualified pension income from a RRIF is tax free up to $2,000 annually. 
In addition, a disability or sabbatical affords an opportunity to turn the tax deferral into a permanent tax savings.

After about $100,000 has been accumulated in an RRSP you can bring the TFSA vs  RRSP arguments into play.