From my experience with the the three main competitors that you listed and your current system components I would recommend the ARC LS25 MKII over the BAT and CAT in your system. I have owned each of these preamplifiers and wound up spending the most time with BAT in my system. I found that when directly compared to the ARC LS25 MKII and the CAT SLI Sig the BAT 30SE sounded slow and compressed. The CAT is the best value in that the line stage was excellent and the phono stage was great. I think that mated with the VT 100 the ARC is better choice. The LS25 MKII was the most dynamic of the bunch. The soundstage extended way beyond the width of the speakers. I think that you should be able to find a used one on Audiogon in the 3K range. I think that the ARC is a great value at that price. The resale value on the ARC is reasonable as long as you purchase it on the used market in the 3K range.
Good luck in your search.
Good luck in your search.