PS Don't mention how you intend to pay until your ready to sign, I took 72 months interest free, why spend your cash thats earning when they'll give you theirs for free. I know nothings free, but they just take it from their advertising budget.
The dealer actually pays for most of the 0% costs. It comes right out of the proceeds from the loan, he gets shorted that amount. It may still be wise to use Mahindra's money instead of yours, but there is no real strategy that changes the numbers. Cash or standard rate gives you the lowest price. As the interest rate gets lower and approaches or hits zero, discounts go away and the unit price effectively goes up.
Some dealers price all the units at the 0% for 84 month price, but they risk people not listening to the discounts available. Those folks will think that dealer is ridiculously high, at least initially. When they hear that dealer is $19,500 for a rig and the other dealer is $17,500 for the same rig, they may not stay on the lot long enough to hear about the cash price.
Some dealers price at the cash price, so they have low pricing. But they risk people getting upset when asking for 0% because the have to factor in that cost and the price then changes upward substantially. When the customer hears that the $17,500 price goes up to $19,500 at 0% for 84 months, he is upset. I'm just making up this $2000 differential as an example, it's an arbitrary number.
Generally people are OK with losing a discount to get 0%, but they hate to pay extra for it. Yet it is the same thing. It is difficult for a dealer to maneuver, but less so if the customer states upfront how he wishes to purchase. And of course it is easier for the customer if the dealer has the price differences at his fingertips as well. Basically, there is some discussion that needs to happen. It would be simpler if there was just one price, but not everyone is at the same place in life, we need options, and options complicate things!
I will give this hint though, the 0% "up charge" factors in the financing cost for a typical sale, perhaps tractor, loader and box scraper. If you also buy a backhoe and/or otherwise load up the rig, the 0% surcharge does not go up even a penny. So even if you are prepared to pay cash, you might want to crunch the numbers on the 0% deal if you are buying a big package.