It is the quality of the backlinks not the quantify. 1 good backlink from an authorative website in your field is worth hundred or even more insignificant backlinks. Moreover, irrelevant links or links from websites with bad reputation can have a negative effect on your website. In summary, numbers don't matter and you can't judge your backlinks with their number.
10K-15K maybe is good and enough.... ----------------------------------------------- Home Improvement I Home Design