I usually order at the end of the season because the discount can be as much as 30 or more percent. I keep them in the unheated garage and plant them in the Spring. Most bloom later than normal about 3 weeks later than the ones in the ground from prior years.
I have done this for 20 yrs. for two reasons. \
First reason..... If I order in the Fall I usually do not get enough good days to go out and plant. Most years we have miserable weather Sept-Nov. We have rain every day, cold, then we go to snow. Very few years do we get nice crisp Fall days. So I ended up most years having to store the bulbs over the winter.
Second reason........they are way cheaper.