There is not enough information here to answer your question. I live in a low cost of living area, so custom cabinets are pretty comparable in price. This may not be true everywhere. Custom cabinets are great if you have specific size needs that are not widely available.

You can also use kitchen cabinets in the bathroom, which might be another price point.

Or...repurpose a nice old dresser or sideboard! They are usually made of solid wood and can add an interesting touch to a room often at less cost than a new pressboard vanity. As you will likely lose the function of some or all of the centre drawers/cupboard, look at the design of the piece carefully.

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