The typical bill for a simple funeral has grown by 7% year on year since 2004, according to a Citizens Advice Scotland report.
It is set against a background of falling household incomes and a cut in the emergency assistance that people can claim for funerals, leaving some families unable to bury their deceased, CAS said.
The most expensive local authority for burials, East Dunbartonshire (£2716), charges four times as much as one of the cheapest, East Renfrewshire (£715). This means there is only seven miles between the most expensive place to be buried on mainland Scotland and one of the cheapest. Only the Western Isles has cheaper burial charges at £680.
The local authority with the second most expensive burial costs was the City of Edinburgh at £2110 followed by the City of Glasgow (£1,962), South Lanarkshire (£1,883) and Stirling (£1,728).
The CAS research shows that the typical costs for burial in a local authority is £1,182 and when charges for the grave site, fees to the undertakers and the coffin are factored in, the average cost of the funeral rises to £3,240.
Cremations also widely differ in price with Perth and Kinross Council being the most expensive (£730) of the 12 councils to offer cremation facilities.
CAS is concerned that some councils have increased their costs in recent years to cover shortfalls in overall budgets or "to bridge the gap between their charges and the national average".
East Dunbartonshire Council raised cemetery charges by 18 per cent in their 2013/2014 budget to "deliver £84,000 of additional income".
In response to questions about the council decision to raise costs by a further 50% in 2014/2015 to raise an extra £89,000, a council spokesman said: "The council had difficult decisions to make while facing increased budgetary pressures. Every effort was made, where possible, to introduce or increase charges for services, rather than removing services.
"We realise that burial charges are a sensitive issue but we promise to work with residents who are struggling to pay these charges in difficult times."
CAS head of policy Susan McPhee said: "It's a lot of money for a family to find at a time of emotional stress - particularly when the bereavement is unexpected," she said.
"So it's even worse to discover that some people are being charged significantly more in burial costs than those in other areas, even just a few miles away."
CAS say the number of people attending their offices over the cost of funerals has risen by 27 per cent in 2013/15 compared to the previous year. The Scottish CAB network is now assisting with just over one case every day regarding the costs of funerals.
"These high costs come at a time when many families are struggling just to feed their families and keep their homes, so a sudden bill of over £3,000 can be devastating," added Ms McPhee.
"To make matters worse, the special assistance scheme that people have been able to claim in the past has been squeezed of resources, so that 50% of applications are now being turned down."
No-one at East Dunbartonshire Council was available for comment.
A Scottish Government spokesman said it gives advice about what to do after a death, including guidance on financial assistance that may be available to families.