Buying fine jewelry can feel confusing if you don't work with it every day.  Here's the honest breakdown of what you're getting and why it's priced the way it is.

What does “solid gold" mean?
Solid gold is all the way through, no plating, nothing to wear off.  Pure gold (24K) is too soft for everyday jewelry, so it gets mixed with other metals for strength: 14K is 58.5% gold throughout the entire piece; 18K = 75% gold; 24K = essentially pure gold

Solid gold vs. Gold plated 

Gold-plated jewelry contains only a thin layer of gold on the surface.  Plating wears away. 
Solid gold wears with you, and retains the value of the gold it contains.

Spot price ≠ jewelry price
Spot price is the market value of raw, pure gold, not a finished piece of jewelry; It's the price of the ingredient, not the finished piece.
Before it’s jewelry, that gold has to be alloyed, designed, cast, hand-assembled, finished, and inspected.  All of that is labor and cost on top of the metal.  Gold prices shift daily too, so my prices can move over time, especially on heavier pieces.  Before a piece is made, it may be designed, modeled in CAD, revised, prototyped, and 3D printed.

What is casting?
Casting is the process of turning a design into gold.  A mold is created from the design, molten gold is poured into it, and once cooled, the rough gold piece is removed and finished by hand.

Casting is only the beginning
A freshly cast piece still needs to be cut, cleaned, filed, assembled, soldered, polished, and finished.  A lot of the work is still done by hand. Technology helps make jewelry accurately, but skilled hands are still needed throughout the process.

Simple looking ≠ simple to make
A necklace may contain dozens or hundreds of individual components, each requiring production, assembly, and finishing.

Weight matters
More gold generally means a higher material cost. Two similar-looking pieces can contain very different amounts of gold.

Same weight ≠ same price
Two pieces with the same gold weight can require very different amounts of design, labor, and production.

Solid ≠ hollow

Both can be made entirely of gold, but hollow construction uses less gold and weighs less than a fully solid piece of the same size.

Heavier ≠ better made
Some pieces are intentionally lighter for comfort. What matters is whether the construction fits the design.

Melt value ≠ retail value

Melt value is the value of the gold contained in the piece. Retail price also accounts for design, labor, production, finishing, and the costs of making and selling it.

Handmade ≠ made without technology
Fine jewelry can combine CAD, 3D printing, casting, lasers, and other equipment with traditional bench work and hand finishing.

Small variations are normal

Casting and hand finishing can create slight differences in weight and finish from one piece to another.

Gold is recoverable, but production isn't free

Scrap gold can often be refined and reused, but handling, refining, equipment, materials, and production still carry costs.

Made to order takes time

A piece may move through design, printing, casting, bench work, finishing, and quality control before it is ready.

Care
Gold won't rust or tarnish and can genuinely last generations, but it's not indestructible, normal wear happens.  Scratches, patina, and gradual wear are normal.  Avoid harsh chemicals, clean gently, get clasps checked periodically if you wear it daily.  Most solid gold can be repaired, resized, or refinished when needed.

Bottom line
You're paying for the gold and everything it took to turn it into something you'd actually want to wear.