D2 has a solid groundwork
For its time it was very good, excluding patch 1.10 which was not meant to be a playable patch but rather a testing patch for D3 ideas
Having modded D2 I can tell you that you can improve the itemization by keeping it Diablo flavoured
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crafting items having a chance to retain the sacrificed items affixes
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unique/set items being salvageable and upgradable Unique & set dismantling demo - YouTube