Jeff: For the money you're talking, I just counted three different 736 Berks with 2046 whistle tenders in the newest LCCA "Interchange Track". Prices ranged from $225.00 (Very Good) to $300.00 (Excellent).
Keep in mind these are LCCA members that sometimes price to the high side (kind of like some dealers that drag the same stuff around for 15 years and never sell it because "Lionel" is worth a small fortune").
I'd spring for a 736 Berk as they are good runners; just be sure to check the siderods for wear + axle bushings for wear s the siderods transfer the motion to the three forward pairs of drivers.
Larry D.