here is a little list of current prices per k in gold coins. This list has not been updated in a year or so but still looks pretty good. feel free to offer new content or comment. for example advanced tools per 1k should be priced around 4000 coins. and so on.
advanced tools 4000
apaper 400
arquebuse 4000
battle horse 500
bean sprouts 7500
beans 3000
book fitting 4000
bows 14
bread 11
brew 20
bronze bars 70
bronze swords 35
cannon 6500
carriages (cannon) 2500
coal 17
coins 1000
copper depo 500
copper ore 45
crossbows 3000
dama swords 2500
ewl 100
ewp 250
fish 16
flour 12
gold bars 500
gold depo 3000
gold ore 450
granite 320
granite depo 1000
grout 80000
guild coins 12000
gunpowder 3500
hwl 10
hwp 20
horses 45
ipaper 90
iron bars 500
iron depo 1000
iron ore 200
ironswords 375
lb 200
maprags 1150
mwl 100
mwp 200
marble 40
meat depo 5
meat 18
mortars 6500
nibs 200
omniseeds 8000
oil 150000
oilseed 10000
pwl 7
pwp 7
plat ore 525
plat bar 900
plat sword 3000
printing letters 400
saddle cloth 1000
salt 1800
salt depo 5000
sausage 35
spaper 100
steel bars 600
steel swords 500
stone 7
titan bars 2200
titan depo 8000
titan ore 3300
tools 45
wagon (mortar) 2000
water 9
wheat 25
wheels 1500
wool 70
woolen cloth 250