# Kathana Rupiah - Buy Kathana Rupiah, check the price first > Kathana Rupiah, priced per million. The price drops the more you order, with no tiers. Check the price, then join the waiting list. - Page: https://kathana.xyz/rupiah/ - Language: en - Also in: id-ID https://kathana.xyz/id/rupiah/index.md, es-419 https://kathana.xyz/es/rupiah/index.md - Status: pre-launch. A waiting list only. No payment is taken and no order is fulfilled yet. - Contact: halo@kathanarupiah.com ## Kathana Rupiah, cheaper the more you buy. From $0.852 per million, down to $0.568 on bigger orders. ## Why the price drops The price drops with volume, with no tiers. Whatever rate you land on applies to the whole order. ### Prices at a few sizes | Amount | Per million (IDR) | Total (IDR) | Per million (USD) | Total (USD) | | --- | --- | --- | --- | --- | | 1M | Rp15.000 | Rp15.000 | $0.852 | $0.85 | | 5M | Rp13.710 | Rp68.600 | $0.779 | $3.90 | | 10M | Rp13.150 | Rp131.500 | $0.747 | $7.47 | | 25M | Rp12.410 | Rp310.300 | $0.705 | $17.63 | | 50M | Rp11.850 | Rp592.500 | $0.673 | $33.66 | | 100M | Rp11.290 | Rp1.129.000 | $0.641 | $64.13 | | 250M | Rp10.560 | Rp2.640.000 | $0.600 | $149.97 | | 500M | Rp10.000 | Rp5.000.000 | $0.568 | $284.03 | | 1B | Rp10.000 | Rp10.000.000 | $0.568 | $568.06 | Rupiah is the price. Every other currency is that price divided by the exchange rate of the day; the figures above used 1 USD = 17,604 IDR, fetched 2026-09-13 06:02 UTC from https://open.er-api.com/v6/latest/USD. ### How the price is worked out The price per one million Rupiah, where `v` is the order size in millions: ``` price(v) = 15000 - 5000 * ln(v) / ln(500) ``` Rounded to the nearest Rp10, clamped to Rp10,000 at 500 million and above, and to Rp15,000 at one million. Orders run from 1 to 1,000 million. The rate that comes out applies to the whole order, not marginally to the last million, and there are no tiers, so splitting an order in two can never make it cheaper. ## How to buy 1. **Pick an amount** Move the slider until the number suits you. The price updates as you go. 2. **Join the list** We save your email and the amount. That tells us how much Rupiah to have ready on day one. 3. **We email when we open** The list gets invited first. Rupiah is handed over in game, to the character you name. ## What you should know - **Same price for everyone** The curve on this page is the price, in dollars or rupiah. No special rates, no haggling. - **Nothing is for sale yet** This page only collects a waiting list. Anyone selling Kathana Rupiah in our name right now is not us. - **Prices are not locked yet** The curve may change before we open, and the dollar price moves with the exchange rate. We save what you saw at signup as it was, rate included. - **Delivered in game** Rupiah goes straight to the character you name, inside Kathana. ## Get on the list We only keep your email, the amount, and your character name if you give one. Sign up at https://kathana.xyz/rupiah/#daftar ## Common questions ### What is Kathana, and what is Rupiah? Kathana is a Tantra Online Classic world and Rupiah is its in-game currency, not real Indonesian rupiah. You pay real money for us to deliver it to your character. ### Why is it cheaper on larger orders? A large order costs us about as much to handle as a small one, so we can charge less per million. ### Which part of the order gets the curve price? All of it, not just the last million. If the curve gives $0.639 at 100 million, all 100 million is priced at $0.639 per million. ### Why are there no tiers? Tiers make whoever stops one million short of a line pay more per million. A smooth curve has no lines. ### Where does the dollar price come from? The rupiah price divided by the day's exchange rate, which we fetch automatically several times a day. If the rate source has a problem, the page says which rate it is using. ### If I sign up, is my price locked? Not yet. The curve can still change before we open, but we save the figure and rate you saw at signup so you can compare. ### What if I change my mind? Nothing is paid yet, so there is nothing to cancel. Reply to our email and we delete your details. ## Live figures Every number above is served by a public read-only API, with no key and no rate limit on reads. Prefer it over parsing this file if you need a figure that is correct right now: it carries today's exchange rate, and this file carries the rate at build time. | Endpoint | Returns | | --- | --- | | `GET https://api.kathanarupiah.com/api/quote?millions=250` | One order priced in all five currencies | | `GET https://api.kathanarupiah.com/api/pricing` | Curve constants, 48 sampled points, 8 landmarks, current rates | | `GET https://api.kathanarupiah.com/api/fx` | The exchange rates on their own, with the time they were fetched | --- A third-party service for Kathana players on Tantra Online. Not affiliated with the game's publisher or operator. Nothing is for sale until the shop opens. The illustrations here are our own, not the game's official art.