Assuming the prices on the wiki are fully up to date: 80*1.25 = 100 for fine longbow, 14,4*5*1.25 = 90 for 5 fine broadheads, for total of 190. Decent reindeer fur is 200.
It does make certain sense to act as middleman though. For example, you could sell your food or extra weapons to villagers for furs, which would indirectly allow you to trade weapons and food to foreign traders. Or you could sell your bigger furs to villagers for winter lynx/beaver/arctic fox furs to make your fur stack more valuable pound for pound when dealing with foreign traders. Or if you see foreign traders near your settlement, you could go load off your large furs for jewelry and random weapons, then use those to buy stuff (possibly the said weight/value effective winter furs) from the villagers. It allows you to concentrate your wealth into more portable form generally. This is useful both because it allows easier management of long shopping trips or just allows you to always have that fat stack of wealth available when you meet foreign trader that has something you really want far out in the wilderness, or it allows you to get past foreign traders' carrying limits (they won't accept more furs than what they can individually carry).