Is March the best time to buy winter clothes at reduced prices ($$% off) or not??
Best thing to do is figure out what you want/need, figure out a budget, then shop online for what's available and offline for better bargains as stores need to turnover to rent paying merchandise.
March, april, may will be one of the "best" time with the greatest selection and some price bargains. June, july, august are going to be the "best" time for price bargains but less selection.
So just depends on what you want.
Just a coat? Do you have a specific coat in mind that you like? Did you find a bunch of different coats you like and just want to choose one?
Do you need a bunch of different stuff? Can you find it all in one place now and save money on shipping? Later you might find one thing at a bunch of different sites or places and may end up losing any savings having to pay for individual item shipping.