If Satoshi becomes so expensive that it cannot be exchanged for anything, it may create some problems for using bitcoin in everyday transactions. However, in this case, there are several possible solutions:

1. Dividing Bitcoin into smaller units: If Satoshi becomes too expensive, it is possible to divide bitcoin into smaller units to facilitate transactions with smaller amounts. For example, you can create a new unit equivalent to 1/100 Satoshi to be able to conduct transactions with smaller amounts.

2. Using Alternative Cryptocurrencies: If Bitcoin becomes impractical for small transactions, people may turn to other cryptocurrencies that may have smaller units or lower transaction fees.

3. Using Secondary markets: If Satoshi becomes too expensive, people can start using secondary markets to exchange Satoshi for other cryptocurrencies or fiat money. This may be inconvenient, but it may be a temporary solution until more efficient ways of sharing become available.

In general, the possibility of Satoshi becoming so expensive that it cannot be exchanged for anything is a theoretical problem, and the market and users are likely to find solutions for such situations.

Hi! If you have a BTC address and password for a brain wallet, then there are several ways to withdraw money.

1. You can use a wallet that supports importing brain wallets. Open such a wallet, select the option "Import wallet" or something similar, and enter your address and password. After that, you will be able to manage your funds and withdraw money.

2. If you have a recovery phrase (seed phrase) for a brain wallet, then you can use it to restore a wallet in another wallet that supports recovery by seed phrase. Enter your recovery phrase and follow the instructions to access your funds.

3. If none of the above is suitable, then it is better to contact the support service of the wallet that you used to create the brain wallet. They can help you with restoring access to funds.

I think your plan can be successful in the long term, especially if you already have experience with Bitcoin. Using $3 a day to buy Bitcoin can lead to accumulating a significant amount over time. Additionally, if your mother already has savings and is working on them, it can be an additional source of funding for her desired Hajj pilgrimage. It is also important to consider the risks associated with investing in cryptocurrency and be prepared for possible market fluctuations.