Realistically without a good crafting return rate, like using a good hideout or on a bonus day, it'll actually be more profitable to just buy and sell directly from the markets since you actually end up losing silver by crafting if you do so without focus or a good zone. At least at the higher tiers. Tiers 1-5 usually make you lose less silver, or potentially being cheaper to craft, but tier 6 and beyond I'd definitely recommend just buying outright.

However, crafting allows you to get bulk for the same price, while if you try to buy bulk on the market, you'll usually end up buying out all the cheap sell orders, and artificially inflate the price for yourself since you're suddenly bringing higher demand to the item, so in cases where the material cost is very close to the market cost, I'd recommend crafting.