I’ve done it before for non-wedding things. I knew I wanted a different credit card once I learned about reward points and I was ready to buy a fence (and installation) which was $11k. Had the money saved already, found a card that would earn me the most rewards plus bonus cash back for spending a certain amount within the first 3 months, as well as have 0% interest for the first 18 months. Paid for the fence with the CC and saved the money in a high yield savings account. Wish I invested it instead for that 18 months but with the interest, CC rewards and bonus it came out to around several hundred dollars of savings. If I had invested it would have been closer to fifteen hundred (edited bc I definitely think the market did very well in that time) dollars a the time. It’s a fairly common approach if you’re comfortable holding debt.