This item can be either be bought from the Vendor in the Marketplace or crafted at the Alchemist with crafting materials.
So it might be interesting to note that to Craft a Health Vial, you need just 380 Gold worth of items (plus 5 Gaia’s Tear, which don’t have a direct Gold price).
If we look at how much Gaia’s Tears cost compared to Gold:
We see that Gold is worth (at the time of writing) almost twice as much as Gaia’s Tears. Prices for tokens in $USD will always fluctuate based on what’s happening on the market, with the prices going up when ingame demand increases and going back down when demand decreases. Free economy, etc. But, for the sake of argument, let’s assume it won’t deviate too far outside of [Gold/4]<Gaia’s Tear>[Gold*4], which would give it a fluid value of 0.25-4 Gold. At most this would put the value of 5 Gaia’s Tears at 20 Gold.
So at most, crafting a Health Vial will only cost 400 Gold worth of resources, compared to the 3,000 Gold upfront cost of the Vendor.
In conclusion – Craft it if you can.
It might also be worth checking out items at the Trader at the Marketplace to see how much liquidity there is in a certain item. Click here for more about the Trader.
At the time of writing, it actually worked out a lot cheaper to buy Health Vials from the Trader:
Click to learn more about Item Liquidity Pools
One reason that Health Vials were so cheap at this point was because Health Vials were one of the items that were airdropped en-masse to winners of an incentive-driven snapshot of every wallet. As there was no need for them prior to the release of PVE and PVP, a lot of people sold these assets off for Jewel liquidity prior to the release of the Crystalvale expansion to invest in the Liquidity Pools (the Ice Gardens).
Once PVE and PVP options are available, these items will significantly increase in demand and the price will go up in the Trader accordingly.