This is probably a really obvious question, but I can't seem to find the answer anywhere. So please excuse me if this is common knowledge!

I tried on a wedding dress I loved a few months ago, and pretty much decided it would be my dress. Then, I lost a bunch of weight and decided to keep looking. I noticed the same designer makes a dress incredibly similar to the one I loved, but with a slimmer silhouette that may flatter (and let's be real: show off) my more svelte (ha!) shape. Of course, now that I want this dress, I can't find a local bridal shop that carries it.
So, after that long and wordy preamble, my question: Can bridal shops order a sample of a gown for me to try on? Is this a normal request or is the dress seller going to look at me like I'm crazy? Is there usually a fee for this sort of thing?
Any advice, experience, etc. are much appreciated! Thanks!!!