Jet,
First off
WELCOME ABOARD! To answer your question, is it foolish to buy a scope that is 4x more expensive than a rifle? NO! Unlike rifles, where you can get a relatively inexpensive rifle that shoots great and is reliable - like your Remington M700, with scopes, and other optics, you generally get what you pay for.
Does that mean that a $1000 scope is 4x better than a $250 scope? Well, yes and no. Keep in mind the economic law of diminishing returns. In this case, you may be spending, say, $500 more for only a 50% improvement. If you would spend $1000 more, then you would get, say, a 60% improvement. But for some people, who want the best, then it may be worth it.
You mention that low light is a must for you. Okay, I can tell you that the LPS is worth the extra money over the Vari-X III. An LPS will cost you about a little under a grand (if you want the 50mm version). A comparable Zeiss will cost you about $250 to $500 more, depending on model. In my opinion, if you want to spend over $1,000, then get a Swarovski with the 30mm tube (a must for low light conditions).
Many people will tell you that an Elite 4200 is more than enough for most legal hunting in the US. Well, yes, that's true, but there is nothing wrong with having more light transmission to make an even better shot.
Another option you have is to take a look at the new Nikon Gold 2.5x-10x-56mm with 30mm tube. They are more expensive than the Monarchs and Vari-X IIIs, but they are less expensive than the LPS, and I think the best buy. In fact, Outdoor Life magazine rated it as the best for low light conditions. I think that the Nikon Gold would be perfect for your .270, and with those HUGE 56mm objectives and 30mm tube, you will probably be able to see the nose hairs of a buck 100 yards away in the middle of the night.
Zachary