Van Engelen is one of my main sources.

https://www.vanengelen.com/

Scheepers/VE or Brent&Beckys. Both carry more interesting bulbs than big box store selections.

Old House Gardens for heirlooms and rare bulbs; Brent & Becky's for both heirloom and general varieties. I've never been disappointed with the bulbs from Messelaar Bulbs Co. Not as well known as other mail order sources, but their bulbs are consistently excellent. Their store in Massachusetts has been in business since the 1940s.

I typically use Home Depot and buy when bulbs are on sale, ive never had a problem with their quality or size of their bulbs. They always come up nice and healthy.

However I only get typical bulbs, so if you want something special you should look at other sources. They aren’t super cheap at HD but definitely a reasonable price. I usually buy Van Zyrden (sp?) brand, this brand is much more expensive on amazon or even at Walmart.

ive even had some decent luck buying tubers and bulbs at Ocean State Job lot, but those are hit or miss and very cheap, and of course only typical varieties

Our Home Depot carries 2 companys' bulbs. One is expensive, the other less than the nursery dept. at Farm Supply or Ace Hardware.

If you have WalMart check their prices.