Is it considered deception and falling into the forbidden to request a beauty service at its normal price without disclosing that one is a bride, in order to avoid paying the higher price designated for brides, knowing that the service is the same in both cases?

This contract is a lease for a known benefit. It is stipulated that both the benefit and the rent must be known to remove ambiguity and prevent disputes, as Allah Almighty says: ﴿O YOU WHO HAVE BELIEVED, DO NOT CONSUME YOUR WEALTH AMONG YOURSELVES UNLAWFULLY, BUT ONLY [IN LAWFUL] TRADE BY MUTUAL CONSENT FROM YOU.﴾ If you describe the desired adornment to the worker, that is sufficient, and your not mentioning that you are a bride does not affect it. As for exploiting the bride's need by increasing the wage fivefold, this is injustice, exploitation, and consuming people's wealth unlawfully, unless the increase is slight and customary for such occasions or in exchange for increased work.