Best wishes. I found many less expensive and newer units online with NO state sales tax. Amazon is really shooting themselves in the foot!
It's like anything else, no retailer, even in e-commerce, has a monolithic, unilateral edge on always providing the lowest price. I've even found situations where brick and mortar stores had better deals than anything I could find online, even after paying sales tax.
The caveat with Amazon is that you don't always have to pay state sales tax, as it depends on the Vendor. I didn't pay any state sales tax on my TRX-2, although I did have to have the 536HP shipped to a friend just across the river in MO to avoid the tax (MO has since required Amazon to collect tax). A lot of times I cannot find the product, at least not brand new, for a competitive price on ebay. This is likely due to the fact that both ebay and Paypal take a cut of the seller's proceeds.
It's just always best to shop around. Where I've actually gotten the most bang for my buck on Amazon is from auto parts, BUT there are sometimes some really low prices on scanners. If you use
https://camelcamelcamel.com/ you can enter the URL of the scanner from Amazon and it will show you the full price history and send notifications when the price drops below a desirable level for you. This is how I snagged the TRX-2 when it fell below $490 last week. Yes, Prime is probably NOT worth the expense if you are only ordering a few hundred dollars worth of merchandise per year.