I "justify" it this way. First of all, US $45k doesn't buy you what it used to. We're talking lightly optioned 3-series money here. You could probably spec a Mini to $45k. So after you get over that "sticker shock" the main deciding factor in my chosing a Morgan over another make was that I wanted something that wouldn't keep me wanting for something else anytime soon.
Case in point, I really like the Boxter Spyder. It's a great car TODAY. Fast forward 3 years and it's a used sportscar rendered obsolete by whatever current Boxster iteration exists. Also, if I got one, I'd still lust for a 911, but couldn't afford one. That;s the problem with P-cars, there's always a step up. 911<911S<9114S<911Turbo<911 GT3<911GT3 RS<911 GT2<and so on and so forth. You don't have that issue with the M3W, there is no comparrison. My heart won't drop when someone with a more "exclusive" variant pulls up beside me. Frankly, there's nothing special about a $100k sportscar anymore anyway. You're not turning any heads. In this thing though... for better or worse you're going to get some attention. I'd say it's the best bang for buck in this regard.
From my previous post about alternative selections you'll notice they are all repros/replicas. The Morgan is the real deal, not a replica. So that carries with it some status that the others lacked.
Realistically, I'll keep the car for probably 15 years or so, if not longer, at which point it will be worth maybe $10K. $30k over that long isn't really a lot of depreciation, relatively speaking. If you add in maintenance, insurance, etc. you'd be well ahead of the game versus almost anything else I could think of.