Not that I know of. But my thought is that the external insulation is so minimal--BSC and Building America recommend a minimum of 2"XPS for high performance in a cold climate--that the wall might still be cool. Plus there's likely extensive thermal bridging at the top and wicking up of moisture through the walls (unless there is insulation under the wall or a thermal break). If it were my home, I'd add at least an inch of high-R foam on the interior as well. And don't forget the rim joist area, either with foam board well sealed, or easier and surer, spray foam. Spray-foaming the rim joist area is an essential step in creating a healthy energy-efficient basement. Here is a link that might be useful: High R Value Foundation Assemblies

I'm going to respond to something you weren't looking for - fiberglass batts on basement walls are not ideal. Yes - it is done all the time but foam is better. I'm not up on all the arguments but the basics are that moisture comes out of the concrete and will cause mold/mildew in the fiberglass. Far better to use rigid foamboard and I am pretty sure that you would be fine with R-8 - which would be 2 sheets thick. You can then put fiberglass on that if you want. Code here would be insulate the floor. Anytime you have unconditioned space next to conditioned, you need to insulate. Even if the basement is always going to be mild temp. I see what you are thinking - get some climate control from the ducting but that isn't allowed. And then maybe some more from the floor above. Fiberglass is cheap. Insulating the floor is the right answer. My builder always insulates the basement floor even on a conditioned walkout basement. The reasons are sound (minimal) and if you don't want to heat the basement at different times then your 1st floor won't suffer.

Note that the slab may or may not be part of the foundation. Given the age of the house, I'm pretty much sure it isn't. It's just a floor someone poured. As Geoffrey says, we can't really guess at prices. Get bids AND REFERENCES. I agree a floor under a 5' ceiling will not really do much for the value of the house, it's really a convenience for you when you're storing stuff in there. Yes you can excavate down, but as Geoffrey says, you need to make sure you're not weakening the existing foundation which on a house of that age could be anything from concrete to brick/block to loose stones/rubble. However, unless you also intend to finish that into habitable space, I agree you'll never recover the costs of doing this in home value.

Bonded Wedi at 1/2" adds aprox R3 more importantly adds/ acts as a thermal break when used on ***top of basement slab, you then add radiant or hydronic heat above wedi. This is smarter than using R-foam below slab in that you no longer have A thick mass of crete to heat up and over work the heat elements (if radiant) to reach desired temp and many times eventually forcing the sensor(s) to fail. It is not cheap but offers a smarter approach and lifecycle by heating the tile and not the entite slab.