Can I wear the bridesmaid dress we agreed on after the bride chose a much dearer one?

The bride posted a $210 dress in our group chat with, "This is the one. Please order tonight." I still had the screenshot where she'd said any dark-blue dress under $100 would work.

I had bought an $82 dress and sent her a photo. She'd replied with a heart and "Perfect." The new dress also has a $40 shipping charge, and the alterations shop quoted me $65 after I showed them the measurements. I haven't ordered it.

When I messaged privately, she said her sister had found the new style and it would make the photos look more coordinated. She offered to lend me the difference until payday. I don't want to borrow money for a replacement dress I didn't choose. I've already booked a $280 room to attend, which was part of the budget I worked out when I agreed to be a bridesmaid.

She's a generous friend who has done a lot of the planning herself. I can see why one decision she thought was finished feels like another argument. But the dress she approved is hanging on my wardrobe door.

Is it reasonable to ask to wear that dress while standing with the others, or should I offer to attend as a guest? I don't want that offer to sound like a punishment.