Get an ExpertFlyer subscription and review the rules of UA's cheapest J cabin fares DEN-DEL. See if you can live with the adv purchase, min stay, day of week, routing, etc. restrictions of the lowest fares*. Use ITA Matrix to find availability of the lowest fares.
* If you can't live with the restrictions it's time for another carrier.
The cheapest UA-coded flights a quick search finds are AC via YYZ, but UA is by no means cheapest Business in the market.