If you're ok with unilluminated, the 3.6-18 Mk5 is a pretty good choice. If you are getting illumination, the price increase is too ridiculous. You can find used/demo 4-16 ATACRs in that $1,750 - $2,000 range, and that's what I think I would choose over the 4-32 and definitely over the 2.5-20 if you are sticking with NF.
@wind gypsy I completely agree: an NX5 (4-20 or 3-15 range) with 'traditional' geometry would be far more interesting than an ultra short with higher magnification ranges. Unless you have a specific reason for an ultra short (i.e. using a clip on, muzzle so close to objective bell that it may cause damage, etc.), there are way too many drawbacks compared to benefits.