I encounter same fate with VIP GOLD PSU few years back, the offline seller quote Rs.500/- less than other seller and as his place was near to me I went there. The cheater seller didn't reveal it till he completed billing/payment etc.
As soon as I complete payment, seller generate invoice and shocked to see that he just provide 2.5 yrs warranty instead of 3 yrs. as the date/month (hand written by someone) is exactly 6 month old from date of my purchase, when I raised voice he told that they already provided me Rs.500/- discount for less warranty??