...Production SQL server. It has 24 Gig of RAM and a 4 Gig page file. Their hosting company said they can increase the page file to a set value, or let Windows manage it...
If SQL Server is properly configured, you shouldn't be hitting the OS page file enough for it to really mater. If Windows sends a page of data to the OS page file that SQL Server thinks is in memory, you're adding extra disk write and read time. SQL Server manages its own memory rather well, so here's some questions to ask your friend:
What do you have Max Server Memory set to in SQL Sever configuration? Is there enough memory for the OS above what threshold you've set?
Are there any other programs besides the database engine using this same server? (SSIS, SSRS, and SSAS count as other programs)
How often is the OS swapping to its page file?
What are the waits that SQL Server is experiencing?