So far reviews for MGS5 are looking quite solid, though I can understand waiting for a sale price. I didn't actually pay retail myself, but lucked out on an NVIDIA promotion for a free download since I was in the market for a GPU.
I'm not going to be able to wait until the new PC is ready to play it, but I can still enjoy the story on potato quality, then get blown away by the visuals later on the new build...