Lots of variables, and not an easy way to determine a value... And of course, the old saying 'What a buyer is willing to pay!' comes into the formula

! And factors about 'age of tires & batteries, any items that are broken or cosmetically in need of attention, etc. - all bake into the formula on value range.
Your profile shows it's a 37', and some higher demand for 32-36' CC's has been the norm - thus 37' fits pretty close to the "Under 40'" buyer's.
From memory, possibly cross fading with Concepts of that era, the Magna could have the mechanical Cummins 8.3, a various HP levels. Or, I think some came with CAT's and even some Detroits too... The engine, could make a difference in pricing. I think, they all were on the Gillig chassis - which is a solid foundation.
Classic era, and looks, for CC's. IF the mostly stock condition is relatively in good shape, or could be brought back up where needed, that ties into the 'retro' fad of higher end older unique vehicles, boats, RV's demand...
Damon Rapozo recently, last year, sold his 92 Magna. Link attached below. Look over his add, compare the condition to your coach. And try some 'fuzzy math', as needed, to up and down to see how your relates... And I believe that the reflected price, was the 'asking' price - have no idea what Damon sold the coach for.
And that leads me to Damon... He'd have a unique perspective on the price point range - as well, he knows not only CC's, but especially 92 magna's - pretty dang well

!
And two major view points on older and finer coaches that I've seen kicked around in the last 3-4 months:
1) RV Market is softening, and thus over supplies occurring - market shifting more to a Buyer's market.
2) Economy uncertainty, is pulling back the planned budget for potential Buyer's - making use RV's more attractive to them.
My personal thoughts? 1) A higher end, well cared for Country Coach - is a great buy/value for a Buyer not wanting to spend multiple $100K's - for a coach today; 2) Higher end models of older Country Coaches, Foretravels, Prevosts, Monacos, Newmars,etc. - will be the sought out older high end coaches for informed Buyer's...
And notice I have no opinion stated on a value range for you coach. You know it's non prime season, and if the coach is in Bozeman - well, hard to sell a coach locally in the winter. So if selling 'now' - that lowers the bargaining position as a seller...
If Damon is not off still taking some 'downtime' after a very busy season. Suggest you reach out to him (Or Louie, Premier) if Damon is off sun bathing somewhere!) for input, and help on selling a coach. Both are straight shooters...
Will follow the thread, and wish you the best of luck,
Smitty
https://damonrapozo.com/inventory/1694949