This is very simple concept of ECONOMICS - "More the demand - High the Price".
But at-least the supplier must give the same product who pays highest price.
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In so called PREMIUM TRAINS of IR where fares are dynamic and rate increases as seats start getting filled, and when last few confirm berths are available- the rate will be highest, and when...
more... it comes to RAC it will not lower the rate. So despite paying highest fare RAC passenger will get half of the berth, and there will be very very least chances of confirmation as these tickets are NON REFUNDABLE.
So who pays the highest fare- get the least product.
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Wah Wah gr8 IR.