Sounds about right, but it apparently offers no discount from MSRP. O'Reilly marks up from MSRP! pfft...
I found the BXT65-850 for $116.96 w/$15 core.
1996 Ford Thunderbird Battery | FordParts.com
Weird thing is, that price only shows in Firefox. No lie! Browse their catalog for 1996 Tbird batteries/electrical using IE or Chrome and their prices come up as full MSRP! I never knew just using FF earned discounts on OEM car parts, but evidently it does!
If you click the link in Chrome, it does pull up the discount, but clicking it in IE doesn't. hmm... I wonder if they know about this.
Suppose I could get my local stealership to match that low price? Cheapest shipping option one-way plus eating the core charge (which is less than shipping the core) would put me at $147.91, well over the $129.95 MSRP.
My local dealers within 25 miles are not listed among fordparts.com's "shopping dealers", so I suspect they won't match that discounted price, which means I'm likely looking at MSRP + tax – so far the lowest price I can likely get that 850 battery for is $140.99.
Btw, this battery is currently unavailable from Amazon, in case anyone was wondering. Just as well, as the 750 version is marked up way beyond MSRP at Amazon, so the 850 no doubt would be as well.