Hi,

I travel with my family to India (MAA) from SFO every Summer. I have been traveling on Singapore airlines for a long time. Last two years, I have been traveling on United through connections in Singapore with the following itinerary:

SFO - SIN on United (on Economy and was upgraded to Biz class )
SIN - MAA on Singapore Airlines or Air India (on Economy). .

For the Summer 2024, I noticed that the Economy tickets from SFO to MAA is around $3400 for a stop-over in SIN, While Tickets on Singapore Airlines (SFO-MAA) with a similar itinerary are around $1800.
However, the following itinerary is cheaper, if bought it two different tickets.
SFO - SIN (on United) - Around $1500
SIN - MAA (on SingaporeAir) - Around $300.

Does anyone know why the connections on United ticket are expensive..? I feel if I buy two different ticket itineraries, then I will have to check-in again at SIN.

Any insights...?

Thanks
...mottai