So lucky! I loved Paris and I look forward to going back again. You will love it.
How long will you be there?
Think of the cost of fabric this way: You're not paying anything for the airfare so right there alone you should treat yourself to some fabric. What I do when I travel to someplace special is I have a sort of general idea of a quilt that I might want to make or I pick out a specific pattern. Then I get enough fabric to do the top and binding. Many times it is a big splurge - My last one involved Liberty Tana Lawn BUT you will have a wonderful keepsake of your trip and later when you're making your quilt and then enjoying it you'll have all those wonderful memories wrapped up in it.
Seriously, how often does a chance like this happen. Splurge - treat yourself. You totally deserve it!