Ask HN: Most development bang for our buck w/o another full time hire?

So, we have a number of projects/tasks in the pipeline and we'd like to increase the pace at which we can knock them out. At the moment, however, we only have 50-75% of what a full-time, salaried developer would cost per month.

So, what's the best way to put that money to work? Try and find someone who will work part-time and salaried? Try to find a contract person? Try to find a small development shop to assist us?

My main fear is that I'll work with someone and then they'll be gone in 3 months.

Has anyone else faced this scenario?