I have a super guilty conscience right now.
I initially got a price quote from a vendor for centerpieces and linens, and thought their quote for centerpieces was way too high, so I went to Pam to get a quote from her. She was super nice-- very responsive and willing to work with me, and explained exactly what I would be getting from her. After getting a better quote from her, I decided to do my centerpieces through her.
I go to tell my initial vendor that I'll be doing centerpieces through Pam, and they price-matched her quote for me so I could get linens, centerpieces and uplighting all done through them (one vendor, easier than working with two- they also offered to waive their service fee). So I just had to drop a note to Pam telling her I couldn't work with her-- after she put together a contract for me and everything.

I know it's not personal, it's business--but this is my attempt at a "make-good" to her. She was really wonderful to work with and get quotes from, so if anyone is looking for reasonable floral and great customer service, here's another recommendation for her!