Tough to beat the pricing on first gen Swarovksi EL's when you find a good deal. The SLC HD's can be found for very respectable prices too if you're willing to be patient.
The release of the NL tanked the resell market for everything else. Fair price for SLCs is under $1500, and ELs can be had for pretty near that price as well. Watch FB marketplace, KSL classifieds, and the RS optics classifieds. Don't be afraid to make offers.
For Leica, I'd stick to Noctovids, but they're rare on the used market. Stick to Victory SF for Zeiss.
I bought a pair of 15x56 SLC WB (non-hd) that were manufactured 2016 that had a few scratches on the lenses from a buddy who hooked me up, sent them in and had the lenses replaced, and they have been nothing short of amazing. They did a phenomenal job getting the binos to essentially new condition inside and out. I have compared them side by side with the HD and there was a negligible difference. If you can find a pair of older alpha glass in good condition you wouldn't be disappointed.