Kentucky
What kind of ammo you lookin’ for? The only stuff I’ve gotten online has been mil. surplus: 8mm, 7.62x39, 7.62x54R, & 7.62x51. If that is what you’re after, there are good deals to be found on the net. You can also locate hard to find ammo online like .351 Winchester. Shop around and look for the best prices (Sportsmansguide.com usually has a good deal), but remember shipping costs will be significant. To really save cash you need to order quite a bit, like 1-5+ cases, or find a company that offers free/reduced shipping.
I would NOT recommend ammunitionstore.com. I got a case of 7.62 NATO from them that was encrusted with corrosion; unshootable and unable to get them to replace it. Still trying, but they seem to have trouble responding to customers (at least to me).
I’m going to make a wild guess here and assume you live in the Bluegrass state. If so, wait about 4 weeks and you should find some good ammo deals at the machinegun shoot (my favorite event till October!) and there are no shipping charges.