Bitcoin is something new.
It is not new and you can not call anything with more than 10 years old is new. You can call it is immature instead.
It seems to defy understanding. Has there ever been a fixed supply money?
Bitcoin's total supply is fixed and well-known, @21 million Bitcoin.
[1]Is there another case of production cost varying directly with product price?
Bitcoin network is operated by Proof-of-Work algorithm and miners confirm transactions as well as find new blocks. There are cost for each new Bitcoin block but the cost per new Bitcoin is different over time.
Why?
- Electricity cost changes with time and with geographical locations
- Assumes that electricity cost is constant (with time and geographical locations), block reward will be halved each 4 year that in turn causes different cost for one new Bitcoin.
- Mining rigs investment costs change with time
- Infrastructure set-up and maintenance cost will be changed with time
- More
Is there anything else with a competitive yet fixed rate of transactability?
Blocks are mined by miners
[2] and there are two main factors on how fast miners will find new blocks:
- Total hashrates on the network
- Current difficulty on the network
- With same difficulty, if network has higher hashrate, blocks will be found faster.
- With same hashrate, if network has higher difficulty, blocks will be found slower.
Averagely, blocks are found each 10 minutes. Transactions will be chosen by miners from tip of mempool. It means if you broadcast your transaction with high fee-rate (sat/virtual byte - vbyte) on tip of mempool, miners will probably choose yours and confirm it firstly.
References
[1]
Block reward[2]
The Mining ecosystem