A 12-string was on my wish list for a long time... I thought it would be cool to build a stable ot instruments that had distinctive sounds from each other and fit different genres. For one reason or another I set my sights on the Ovation's Adamas 1598 ME-II https://www.cathedralguitar.com/Auction/Adamas1598/Adamas1598.html. On the other hand, I wasn't much interested in the prices the guitar was fetching.
I decided to practice patience and put the web to work for me. I created a Google Alert for the guitar and let it do the watching and searching for me. It took awhile but eventually one showed up at Sweetwater... brand new and well under half of MSRP and about a thousand under what dealers were selling it for. I called Sweetwater and after being assured there was nothing wrong with the guitar I took the bait. I never regretted the decision and the instrument is a beauty.
You might try the same... let Google do the work for you. Set up an Alert, maybe multiple ones for different guitars, sit back and see what shows up.
FYI, my Ovation certainly doesn't sound like a mandolin to me,YMMV. However, this particular model is not easy to find anymore and may be appreciating in price.
"It takes a lot of devotion and work, or maybe I should say play, because if you love it, that's what it amounts to. I haven't found any shortcuts, and I've been looking for a long time."
-- Chet Atkins