There are these on Reverb..
Triungulo Lab Barbanera Low Pass Filter (Moog MF-101 Reissue) Moogerfooger | Viviana's Boutique | Reverb.
View attachment 3731610
Not tried one though and they're pretty much the same price as a Moog MF-101.
I've seen some original MF-101's go on eBay far cheaper than $400 recently, so you may be lucky if you hold out.
Iron Ether Xerograph Deluxe is pretty similar especially with the slow synthy sweeps with an expression pedal.
The Source Audio C4 and Spectrum can also emulate the Moog and do a lot more besides.
It won't help your GAS but a MF-101 on its own is a great filter. With an expression pedal it's an amazing filter, really flexible. Combine it with a Moog CP-251 and it is out of this world.