I have received multiple offers and in all fairness, I will ask for your highest and best offer by 5:00 pm EST tomorrow March 15th
Interesting. This is not an auction or sale site, though there is a classifieds section for those wishing to sell an item but without the protections of sale sites such as ebay and etsy. Most things here are done by "gentlemen's" agreement, so to speak. Folks are encouraged to set a price and accept reasonable offers, if they so desire. Though OBO doesn't restrict one to offering less, I think a consensus would be that the best offer under the asking price would be what is accepted. When one makes a post saying that the hat will sell for $275 or OBO and someone replies "I'll take it", it's usually a done deal. The hat just sold for $275. I guess not.
I was interested in the hat and even sent a PM before I realized someone had agreed to your asking price and I backed away. There will be those that are happy with your decision and anxiously await your response to their offer, tomorrow and there will be some such as me, that will only wish you luck in your further endeavors, we just hope you don't do them here.