In my lowly opinion, any good (and I reiterate the word "good") S2a is worth around $10-11k. That price is for a guideline price for a vehicle in "mickey mouse" mechanical condition and of a similar standard of presentation. Of course the "rarity" factor could influence your figure to some extent but not by too much. (eg. Most 88s are reasonably rare compared to the much more common 109 GS- then of course there are the more specialised versions such as gunbuggies, ambos., wksps, FFRs, etc.)
For this money I would expect a fully rebuilt, restored and well presented vehicle that is registered, (or in the case of Hysterical rego,- register-able) historically correct, on an "as new" rust free firewall and chassis, and that I could confidently park in the garage or drive anywhere without putting as much as a screwdriver to it.
Taking this base figure, and in the case where the vehicle is not as previously described and will require work to bring it up to this standard, it is then up to the purchaser to accurately calculate how much it is going to cost to bring it up to the required standard and start deducting that calculated amount from the original figure.
As a guide, when I resurrected Onslow I kept every receipt for every part I purchased including stupid little items like masking tape, electrical joiners and other trivial parts as well as any major outsourced jobs. Onslow came straight from the military apart from 1 previous owner who didn't touch him at all in the time he had him) These receipts added up to just in excess of $11000.
I am very happy with that figure as I have ended up with a pretty rare vehicle type (and one that holds a lot of personal nostalgic historic value for me ) and a second hand vehicle that boasts basically; a) rebuilt engine, b) rebuilt gearbox and Tfr case, c) completely stripped down and rebuilt body, d) complete new clutch and brake system.....and the list goes on.
The enclosed picture shows Onslow when I brought him home and also on a later Anzac Day appearance, and on the lower level, Daisy as I bought her and at the same Anzac Day march.
Daisy was dearer to buy initially than Onslow but cheaper to restore, with the combined total adding up very close to the $11000 mark strangely.
My Series one was a bit sad when I purchased it for around $1000, but today she is re registered with a completely refurbished engine, gearbox and transfer case, a nice new paint job and some (not all) of the lifetime of accumulated character marks prettied up, new glass, gauges and mirrors: and guess what?
The tallied receipts add up to just in excess of.......$11000.
If you want it, its worth what you are prepared to pay for it.
Regards
Glen