I literally clicked pay and then boom, price goes up
Trying again
On United.com?
I already booked a few of these.
There is a trick I use sometimes with United.com where you select "other form of payment" and choose "Pay in person". Choose either airport counter or united ticket office and click on the purchase.
Effectively, this places the ticket on hold for about a day and issues a PNR number.
Once you have the PNR number, you can find your booking under "My trips" and click purchase now. You can then pay by CC without the price changing.