Motorcycle tire prices vary from vendor to vendor and week to week so it's a good idea to check around for current pricing when buying tires as no vendor seems to be consistently the lowest.
Attached is the spreadsheet (Microsoft Excel 2003) that I use for checking out tire prices in the US for Pilot Road 2s and BT-023 tires. It has hyperlinks for those tires for sale at the usual suspects.
Many tire sellers guarantee the lowest price and Dennis Kirk has a "beat it by a buck" guarantee so if you have a preferred vendor you can take advantage of their guarantee.
Note that many vendors ship tires from the same generic tire distribution centers scattered about the country and others ship from their own on-hand stock so if you need tires quickly it is better to order from one that ships from a DC. For example: The closest tire DC to me is in Idaho and when I get them from there they usually get here the next day if I order in the morning. It's hard to tell ahead of time where they'll ship from so here are the locations for the shops listed in my spreadsheet. If their web page lists an on-hand amount then that's a good indicator that they ship from their own location. Order from the one closest to you if getting a tire is time critical. Or you could call them and ask them where their tires get shipped from.
Here's where each company is located:
Bike Bandit: Near San Diego.
RevZilla: Warehouses in Vegas and Philly.
Motorcycle Superstore: DCs in Medford, OR and Louisville, KY. (Pretty quick if you live on the I-5 corridor.)
Rocky Mountain: Payson, UT.
SportBikeTrackGear: Shelby, MI.
Competition Accessories: Rock Hill, SC.
Dennis Kirk: Rush City, MN. (I know that they ship from their own warehouse because I made my last tire purchase there.)
Chapparal: San Bernadino
Attached are my hyperlinked spreadsheet and a screen print of today's tire prices.