Broken hearted...magnepan and vandersteen

@glfrancis2
Sounds like y'all shopped at HiFi Buys in ATL.
I bought my system from them: Quatro CT powered by Parasound A21 with Bluesound Vault as source via Parasound JC2BP.
Very happy with sound. And, great people and environment at HiFi Buys. David White there is an electrical engineer by training; he knows his stuff, no BS.

You might consider pairing Quatros with Parasound JC5 and NAD Masters series dac/streamer that eliminates need for pre-amp, if you are cool with all digital set-up.

I too planned to spend a lot less money but my wife like your fiance heard the Quatros and opened the door to getting them.
When your partner gives a gift like that, only wise move is to affirm her.

Besides comparing a $2200 pair of speakers to a pair of $15,000 speakers, it would be best albeit difficult to compare the Vandys to a higher priced pair of Maggies but with the following tweaks to optimize the Maggies. These would include mounting them on MyeStands, installing the Mike Powell silver upgrades to the stock jumpers and fuses. Plus Maggies require more power, proper placement away from the rear wall and angulation to optimize the sweet spot with regard to the listening position. All of these tweaks bring out the best in Maggies. They have in my 1.7i pair. 

IF you want the Maggie’s to do what Quattro can do on the low end, you are in to subs and the right amplifiers to drive the main panels, total system cost is about the same ....

kenjitholidayinn let us know when Wilson, Magico exceed 250 K speaker pairs sold, your idea of “niche” may need redefining. Steep slopes with a singular focus on frequency response are easy, I did those in 1980, graduating to time and phase are another matter. But a few intrepid souls have worked this vein, some deceased but legendary- can you name them  from your position of internet obscurity?

Also full disclosure, while I don’t currently own a set of Magneplaners I have in the past and also sold them for many years. The current stable includes Klipsch, Thiel, Quad, Dynaco , ADS , Totem and Vandersteen 

The new Spatial  audio labs  x5, and x3 have world class Beyma tweeter- mid
and excellent German dipole midrange, and powered sub in these great open baffle speakers in the $6k, $7500range they shoot Waay  above that 
and free delivery,and a 60 day audition return policy they are that good.
check these out ihave owned all types Maggie ml, pure audio project 
these are a a Rare breed these latest from Clayton Shaw are only a few months 
old on audio circle a very good utube video,or utube. Check them out 
I am saving as we speak ,and because they are powered for the sub 8 ohms 
97 dB efficient !!