I guess it depends on your year and engine for the TB. I have a 2006 with 4.2. A different coil than yours, but they have yours for $35 each delivered in two days if you have Prime.
On Amazon the price can flucuate throughout the day. Sometimes i put stuff in my wishlist and the price will go up or down. So today the coils are $24.74, when i bought mine they were $23.01 delivered and no sales tax.
Plugs were 6.35 plus $2.00 rebate so in the end they will be $4.35 Could have gotten them for $5.something but it wasn't through Amazon and the shipping would have been 4-5 days. I wanted them quick so i paid a buck more.
I have ordered the whole front end for my 65 mustang, Camry struts, idler arm, etc. Nissan radiator fan. You name it, you can get most parts here if you can wait a few days for delivery.
If Amazon has a warehouse in your state you may need to pay sales tax.