The idea is to capture whatever authority/trust the domains still have. In order to do this, you should research the domains on the waybackmachine. You should then align the new site with the old niche and content.
I've done this with a '01 domain that I picked up for registration fee. The site is ranking for the the targeted keywords with minimal link building.
For content, you should be able to find writers in the NetBuilders marketplace that produce articles at good rates.