Would this work in a society?

[Seretur]

In Dal society an item's/object's worth is determined by it's practical value rather than a form of monetary (check spelling) value. So steel would have more value than gold as, even though the gold is rarer and desireable in most cultures, it has more practical uses e.g. if you're looking to outfit an army or a labour crew your not going to give them golden equipment with is heavy but soft when you can give them steel or iron equipment which is more readily available and more durable; gold is still are nice commidty amogst the high nobility who can afford it.

This is the only objection I have. You say that worth is determined by practical value, which would work, if your culture is very Spartan and doesn't care for beauty. However, if gold is a nice commodity, and is expensive, as the underlined portion indicates, then your culture does value things based on beauty as well as worth.

So in Dal society, when dealing with large amounts of material and goods the unit system is used and when dealing with smaller goods or services the commidity currency is used. Trade offices are also located in each settlement with substantial trade activity to regulate these dealings and to help people convert raw goods into commodity currency and vica-versa. Would such a system seem feasible?

Absolutely. As mearrin said, the Romans did it for hundreds of years, with salt.