Its not legal but Apple dealer or even the company does not care reason is demand and supply buyers are ready to pay the premium to get the devices on the launch day. Also all this is being done by the dealers and not Apple.
13 pro max is being sold at premium of 15k/20k, Even today someone I know bought the 13 pro max 128gb for 148k which is 18k premium over the current retail price, Before launch price for 13 Pro max was 155k for the global device which does not comes with a invoice.
They gave me 2 options either get the 3rd party insurance which is for 21k or take Beats studio buds, Me and my friend We bought 2 devices both 13 pro max 256gb we bargained and settled for these 2.