Thank you all! Those are great points and questions.
This particular festival is in a small town of only 11,000. It's rural but close to larger cities, and is the type of place that highly values local merchants (no department stores within city limits, etc). So the attendance is small, but I feel it would be high quality attendance, particularly being so near Christmas.
As for the rest of the points that soapbuddy mentioned---how long the festival has been running, whether similar vendors are currently enrolled---I passed those concerns on to the coordinator and am waiting to hear back.
Thank you again! It's certainly a gamble and a lot of work to do these things, but the reward can really be worth it... sometimes