Preamp under $2,000.

Check the gain on LTA. Could not get it past ten o’clock in my system. Sounds good though. 

Check reviews on the Schiit Audio Freyda. Supposed to be excellent, Under a grand tube hybrid. 
I think they are enjoying a surge in sales and there is a wait on products.
I am waiting for my Raganok integrated.
My Sciit has been backed up several weeks. 

Belles Aria Preamp is excellent. Made in the USA.

If interested in a tube based pre I would check into Quicksilver or Aric Audio.

I am an MF Dealer.  The older M6 is a nice unit.  It was replaced with an M6s Pre that retails for $1890 so $1500 for an older unit is not a particularly good deal.  

It is detailed and relatively neutral.  Like most MF products, it is made in Taiwan which results in a strong value.  They have been shifting some production to the EU but I don't think this is one of the units that has moved.  For the money, it is brilliant.  

Most places will give you 10% off and free shipping on a new unit which will put you within spiting distance in terms of price on the used unit.  

The other unit I would look at seriously if you can find one is the Ayre K-5xeMP.  You should be able to get this For $1700 to $1900 used and it is worth every nickle.  I used one for years and loved it.  Probably the item I regret selling the most.