no_frills
213
Mech, as usual, makes an important point here
Merke, do you really think the 5970 is the piece for you? It is larger than the 3970, boasts a tachymetre/track that renders it a bit more "sporty" than the 3970 (in my opinion), and the pushers and lugs are a bit different (some would say better, but that's a matter of opinion too).
I personally prefer the 3970 so making the choice is easy. Even if the two pieces were priced the same I'd still go for the 3970 - I like its size, "vintage" look, round pushers, etc more than the 5970. However, some people vastly prefer the 5970... and even Patek claims to have spent 2-3 years working on the design of the 5970 so that they could "set it apart" from the 3970.
So for me, the 3970 is the real winner. Being able to purchase a 3940 in addition to getting a 3970 for more or less the same price as a 5970 is just icing on the cake (since I love, love, love the 3940 too). However, as Mech pointed out, is there no part of you that feels that you're compromising because you really, really, really, actually want the 5970... but you're "settling" for a 3970 + 3940 because "it's a better (financial) deal"?
I would personally go for what I really want, the tradeoff between one versus two watches aside. If I had a choice between getting a 3940P versus getting a Nautilus 5711/1A + Calatrava 5119R (more or less the same price) I would go for the 3940P in a heartbeat... even though the other two pieces are truly lovely watches, if I didn't have a 3940P in my collection I'd feel like I was "compromising." And I'd keep on dreaming of the 3940P anyway!
So, you may well have made up your mind already but just wanted to second Mech's point here.