This is an aspect of ancient
lamps that is indeed fascinating - how the objects related to their social context rather than merely identifying the objects themselves. I certainly remember reading research into the relative
contemporary value of
lamps from at least one region during
Roman times - and I'm sure there is similar research relating to the era of Classical
Greece too (very possibly in
Howland or
Broneer) - but sadly I cannot remember the details. Most of my books, archives and research material are in storage at present and inaccessible so I don't even have the chance to refresh my memory at the moment!
Certainly, basic
pottery lamps, apparently used for
votive purposes and numbering literally in their thousands, have been found buried in pits at temple sites in
Greece - suggesting they were extremely
cheap - but that's all a
bit vaguer than the info you really want. If I come across anything a
bit more specific I'll post it here.
