Local Jag dealer (the one I like, not the one I despise) sent me a coupon for a trans fluid flush for $199. I know I can do it myself, but we all know to do it right (the whole 95 degrees check) we need the dealer tools. So considering that I'd spend about $100 on good oil, $100 sounds reasonable for labor.

I don't know, what you guys think?

sounds about right for a jag dealer...my old ford truck was about $100 at the dealer, and that was a good few years ago.
Are they disconnecting the trans fluid lines and connecting them to a flush machine?

The coupon said tanny flush, so I hope they truly mean a complete flush, and not a drain and refill. I know the service rep, so I'll call her up and double check before taking it in. Maybe she can cut me a deal on the transfer case as well, get both over with as the car is just shy of reaching 50K.

I recently took a friends bmw x3 to a bmw dealer for a trans flush..they wanted $450 to replace filter and flush the trans. When I asked how they did their flush, they said they would refill what came out of the drain pan. So when I pointed out that only a fraction of oil is in the pan ...they said.."we know"
So for sure ask how they will be doing it

If you dont know that trans flushes have been performed regularly since the vehicle was new, do not have them flush the trans because the pressure they flush with will break off chunks in the trans which can get dislodged and ruin your trans.