Cultural armor is great armor if you have the deep pocketbook to afford it. Since it can only be made my high level smiths using hard to obtain components, it can be quite pricey. If you are interested in obtaining some pieces first check the Bazaar to determine if any is available and the going rates. You also will want to compare other types of armor, for the lower end cultural have been succeeded with other armor that sometimes offers better stats. If you are really a glutton for extreme punishment consider taking up blacksmithing and eventually making it yourself (the most costly solution but eventually you can resell pieces).
Some of the diety specific items do have a rather limited market, hence the price "might" be lower because there are much less interested buyers. If the seller is also the crafter (instead of a middleman marking it up) often the price is a little over cost, mostly because the person doesn't want to sit forever on inventory. For dwarven cultural your options are rather confusing. The best is the Underfoot series which is only usable at level 45. The lesser culturals are either enchanted or imbued, and may or may not be diety specific. Before buying study the stats of the piece very carefully to determine if there are any restrictions.
Some examples: (stats taken from eqtraders)
Underfoot Platemail Breastplate
MAGIC ITEM
Slot: CHEST
AC: 51
STA: +5 WIS: +10 HP: +40 MANA: +40
Recommended level of 45
WT: 3.0 Size: LARGE
Class: WAR CLR PAL
Race: HEF DWF HFL GNM
Deity: Brell Serilis
Dwarven Plate Breastplate
MAGIC ITEM
Slot: CHEST
AC: 24
SV FIRE: +5
WT: 11.5 Size: LARGE
Class: WAR CLR PAL SHD
Race: DWF HFL GNM
Dwarven Plate Breastplate
MAGIC ITEM
Slot: CHEST
AC: 30
STR: +8 STA: +10 WIS: +4
SV FIRE: +5
WT: 11.5 Size: LARGE
Class: WAR CLR PAL
Race: DWF HFL GNM
Deity: Brell Serilis
Enchanted Dwarven Breastplate
MAGIC ITEM
Slot: CHEST
AC: 30
STR: +8 STA: +10
SV FIRE: +5
WT: 11.5 Size: LARGE
Class: WAR CLR PAL SHD
Race: DWF HFL GNM FRG
Imbued Dwarven Breastplate
MAGIC ITEM
Slot: CHEST
AC: 24
WIS: +4
SV FIRE: +5
WT: 11.5 Size: LARGE
Class: WAR CLR PAL SHD
Race: DWF HFL GNM
Deity: Brell Serilis