The cost to send money within the US via Western Union depends on the amount you are sending, your payment method and how your recipient would like to receive their cash. To send $100 from your bank account to their bank account still carries a significant fee of $14.00.
If your brother residing in UAE sends money to you in India, the money is not taxable in India. As per the Indian Income Tax Act, money received as a gift from a relative is not considered as income and therefore is not taxable. A relative is defined as spouse, brother, sister, brother or sister of the spouse, brother or sister of either of the parents, any lineal ascendant or descendant. However, it's worth noting that your brother might be subject to taxes in the UAE for sending money out of the country. It's recommended to check with a tax professional in the UAE to understand the tax implications for your brother.