Hi Cheryl
The phrase 'paupers graves' is a bit of a misnomer, families have always paid for their loved ones to be buried either in a churchyard if they were 'of the parish' or in a municipal cemetery unless they were so poor that the board of guardians paid. You usually find that this type of 'poor' family has been receiving parish relief and were always in and out of the workhouse.
Common or public graves in municipal cemeteries exist because families can't afford the outright purchase of the grave, private graves have always been expensive and today costs thousands of pounds, that is if there is still space in them.
Headstones also have been expensive and the family may just not have been able to afford one on top of all the other bills that needed paying.
In your case you need to find out where the church burial registers have been deposited but also look to see if the day books survive because it is the day books which contain the details as to who paid what and for which plot.