few things i can note off the top of my head
like pudin said, scrap banking (albeit not as relevant in 2014 as it was years prior) and crafting hats/rare weps (awp, maul, three-rune etc) was actually lucrative as keys were still worth somewhere in the range of 7-17 ref (i dont have the number off the top of my head), therefore ref was still worth a considerable amount of USD and so were the hats and weapons
earbuds were used as a currency in high tier trading instead of keys. buds were very volatile in price, if your unusual was worth 10 buds, it could've been worth 10x(10 keys per bud) or 10x(20 keys per bud) which tripped some people up.
there were regular major content updates and brought unique changes and additions, unlike the stale and repetitive case updates we have today. new weapons, new festives (festivizers did not exist, only OG festives), balance changes (buffs and nerfs affected prices), new crates, new stranges all kept the economy interesting and changing.
unusual taunts just got introduced around 2014. they were incredibly rare and VERY expensive since they were only from the reel crates. unusualifiers did not exist and there were few effects in the pool.
people saw 1st gen effects as the end-game god tiers. the unlocked (multiclass) crates were not introduced yet so all classes in particular held high values. Burning KEs back then were like 4000-6000 keys as a reference. halloween effects were much cheaper in this era albeit some were still up there
no warpaints, no graded cosmetic case system. just good ol crates where you could get new effects on most old hats
automated trading (bots) was not as relevant back then (other than scrap.tf). most people used sites such as TF2Outpost to trade p2p. there were different trade servers back then (such as PPM, pink taco)
having a loadout such as earbuds + bills made you look like the coolest kid on the block lol
subpoint on this, there were way less hats and effects back then so loadouts were less unique. there was a much more generally-known consensus on what was high tier and what was low tier. nowadays it can be less clear with all the new hats and effects put out every year (i cant even remember every effect in the game anymore)
not TF2 related, but CSGO skin trading was popping off. there of course was no 7 day trade hold back then for CSGO so there was a lot of P2P trading in CS along with trading between CSGO-TF2. nowadays, CS trading is much more cut-throat with the prices, cash oriented, and pretty dry in terms of P2P
remember when they would put new hats into the crafting pool and you could get craft #s? good times, when an update adding hats into the craft pool dropped, everyone would scurry to try to craft some craft #s lol
and yeah like russ said unusual miscs were unboxable and much cheaper