What is the dollar value in Bscscan?

Every transaction says the amount of tokens swapped as well as (I think) the $ value of the token.

As an example, here 2.041470964161454932 WBNB were received with a dollar value of $969.29 https://www.bscscan.com/tx/0x6ec2c124dd4a0914ea1e6d0fe64e5baf99fe347544f956748ec5ed5c1dfa12ad

1. Is this the value of the said token in $ at the moment of the sale or right now? If you pass the cursor over the WBNB amount it says 'current price: $...'
2. How is it computed? Is it based on the price at some exchange?
3. Why does it not match the value of the token it was swapped for? Here the BSC-USD was $970 so there's a small difference that I've noticed every time I do a swap.

When I want to swap two tokens I usually swap for BUSD first, so that I can have a 'dollar value' that I can log as the sale amount and then as the buy amount.

I would like to understand how I can rely on Bscscan to get a $ value of the swap, saving myself the gas fees of doing token1->BUSD->token2 by doing directly token1->token2 instead.