Stale Hardcoded Crypto Fallback Prices

[ameyvaidya44]

Severity: Medium-High

When the pricing API fails, the system falls back to hardcoded cryptocurrency prices. These values can become outdated quickly due to market volatility.

Risks include:

Undercharging users (revenue loss)
Overcharging users (user dissatisfaction or legal risk)
Inconsistent pricing

There is no:

Timestamp validation
Price sanity checks
Slippage tolerance

Why this matters:
Accurate pricing is critical in financial transactions. Using stale data can create both financial and reputational damage.

What’s needed:

Reliable price feeds with fallback providers
Time-based invalidation of cached prices
Bounds checking and slippage protection

[Saranyadharani]

Hi @ameyvaidya44

I'd like to work on this issue!

My approach for Issue #55:

1. Replace hardcoded prices with multiple fallback API providers
2. Add timestamp validation (reject prices older than X minutes)
3. Implement price sanity checks (reject outliers beyond X%)
4. Add slippage tolerance configuration

For Issue #54:

1. Add URL.revokeObjectURL() after all createObjectURL() calls
2. Clean up canvas elements and null references
3. Add React useEffect cleanup functions

Also, could you please add the NSoC'26 label to these issues for tracking?

Please assign me this issue

Thanks!