What a rebalance costs

Which cost of a trade stays roughly the same whether you sell $500 or $50,000?

• The trading fee
• Price impact
• Network gas

In the UK, how is the cost of the tokens you sell usually worked out?

• From the oldest units you bought
• From the pooled average cost of all your tokens of that type, unless same-day or 30-day rules apply
• From whichever units you choose