What should I do?

I’m buying a high chair banner, for my sons first birthday, on Facebook.

I want

A. The better looking one. $5. But she was really flakey with response.

So I messaged

B. The not so better looking one. $10.

And agreed to buy from B tonight.

But then an hour after I agreed with B, A responded saying I could come tonight at 730.

I’d much rather have A. But I feel bad because I already agreed to B, also.

Would you just buy A, B, or both? 🙈

I don’t really want to buy both as I only need one.

But I don’t know what to say to B without being rude.

Please give advice- I have 30 min until 730.