Thanks, everyone. I appreciate your responses. I haven't heard back from them yet, but I'll see what happens. At least I know I'm in the ballpark.
I'm a hobby caker. Most of the cakes I have done have been for relatives and close friends, although I have done a couple I've charged for. This client is an acquaintance. They saw the cake I did for a common relative's baby shower, which I did for free, and asked if I could do a cake for their babe's first birthday. They knew it wouldn't be free, but I'm not sure if they're familiar with cake prices and may not have been prepared for the price I quoted them. They didn't mention a smash cake, but when I gave them my rough quote, I asked if they wanted a smash cake as well.
One of our local grocery stores offers a free cake (2-layer buttercreamed sheet cake with minimal decorations) for a child's first birthday. The potential client is aware of this and might go that route - that's up to them and I'm ok with that. However, if they also think a smash cake would be a cool idea, I'm happy to do one, but I will charge appropriately - obviously more than the $10 I was thinking of if I was also doing the main birthday cake.
I really want to do their cake, though. I have some great ideas, and the more I do, the more I learn and the better I get. But, as my husband keep reminding me, "You can't do everyone a free cake, you know!!!"
Yes, dear...I know.