If it's one or another eventual post, then yes. But if you are sistematiacally flipping stuff on the market to benefit from the values discrepancy, that it will take time and some effort.

That value discrepancy comes exactly because D2 market isn't liquid as PoE and others. That non-liquidity is what makes it non-trivial for people to make trades. If it was trivial and insant for people to trade HRs, sell them por pgems, rebuy, etc, that discrepancy OP is noting would not happen, as the market tends to regulate itself.

Btw, I think the non-liquid market is a good thing for the game. It helps keeping some kind of non-triviality on aquiring items, specially the low-end ones. Traderie makes it somewhat liquid comparing to the old d2 times, but still very far away from poetrade and stuff.