Yes. Bidders must match the price of the driver (depending on their WDC sitting).
If you are making a bid on Diego Campos who is currently sitting 24th in the WDC; his minimum price would be £500,000. (see driver auctions on website). Your bid must match that price.
Now, if Diego Campos wins the next race and say, moves up to 10th in the WDC; his new minimum price would be £5,500,000 (see driver auctions on website). Your bid must then match the new price.
If you place a bid on Diego Campos, which would be no less than £500,000; you must wait 6 days with no further bidders, interruptions. If the 6 days pass successfully with no other bidders; you will sign Diego Campos. (I would message you a confirmation message).
Now that you have signed Diego Campos, that is it, he is contracted to your team for the following season. It would not matter what position he finishes in the WDC.
If you have made your £500,000 bid on Diego Campos, and than 2 days later another team manager places a a higher bid on him that yours; a further 6 days would be added to the negotiation period.