Again, the quality, size, style and color of stones and metals factor greatly into the cost of a wedding band. Precious metals and stones are precious for a reason, as it takes great effort and expense to source them, prepare them, heat-treat them and craft their settings and overall ring design.
For this budget line item, you have two rings at least to prepare for. And in the case of stacking multiple rings, which may be your chosen style or if you have children for whom you'd like to wear 'parents' rings' with your wedding bands, prices will go up for metals, crafting and market value.
Again, this is a meaningful ring you'll always wear, with as much if not greater emotion attached to it, and ring designers and artisans put extra detail into these rings knowing the emotional weight of them. Perfection may be the goal for any ring's stones, but it's the perfection of the relationship that is reflected in the choice of these rings.
Rarity is also a factor. There are only so many stones in existence, with the earth pressuring others over long periods of time. This isn't a floral arrangement. It takes an almost incomprehensible amount of time and effort to create the ring sitting in that glass case, lit brilliantly, sparkling. And it takes a very long time for ring designers to create those stunning ring designs you see as well.
It may seem like it shouldn't cost much to repurpose an existing heirloom stone into a ring, but that process actually takes far more detail and effort than you might expect, so that the stone is well-fit into the setting, the metals looking perfect with the stones, or the right stone found and perfected to fit into your heirloom setting. Ring design processes consist of many steps, high technology levels, special heat treatments to bring out the colors of gemstones and diamonds, and lasers may also be used to help create your ring designs for both engagement and wedding rings.
Even those smooth, simple-looking metal bands worn by men rack up healthy costs, as the ring designer perfects the metals, creates a flawless surface, creates a comfort setting and subtly angled edges. As with more forms of art, the simpler it looks, the more than went into it.
The fact that ring appraisal and insurance is highly recommended for engagement and wedding rings tells the tale: these are valuable items on so many levels.