I'm interested in maintaining a copy of the type of data available at ftp://ftp.arin.net/pub/rr/arin.db however the arin.db file seems to be missing quite a few resources which are available via the ARIN Whois-RWS search.
While it isn't out of the question to query ARIN whenever a lookup needs to be performed, I'd really prefer to have the source data.
Given the number of other sites which appear to have access to a more complete and accurate copy of the routing registry data, am I looking in the wrong place or do I need to pay/register to get accurate data?
No, you can't get it unless you fit the qualifications for a bulk whois from arin:
What the other sites are doing is querying ARIN's API