your wife's budget, it is quite challenging.
If to get something more common, quite many can fit into that range. I hope you will ink and use the pen.
Getting a bit concern when the word collecting come into the picture.
As I am more of a Japanese FP enthusiast, and you would like a catridge, I suggest getting a Sailor 1911 but with a Nagahara Nib. However you may need to top up a bit and go to the pen-shop to dip-try if you like the writing and feeling the pen provides.
There is one which is really good but not a catridge is the Sailor REALO.
Something more practical, would get a Pilot Capless or even the Lamy Dialog 3 Fountain PenLamy Dialog 3 Fountain Pen