Okay well…
D5k- has significantly more megapixel, does video (you said you don’t care about that though), a faster continuous shooting feature (could be seriously helpful if you shoot sports).
D3k- a great camera with significantly less features but potentially plenty of camera too.
The difference in price is 20%. I feel like you’re getting at least 20% more camera with the D5k so it’s really more about whether or not you’ll use the features that the D5k has and the D3k doesn’t. For the record those things seem to include:
1. Video
2. Variable angle LCD monitor (as opposed to fixed)
3. 12.3 megapixel (as opposed to 10.2)
4. continuous shooting as fast as 4 fps (as opposed to 3 fps)
5. Seriously better low-light shooting (you can check the low-noise ISO specs)
6. Easy live view (I’d have to use it to know if it’s worthwhile but it could be a very convenient feature)
7. etc.
Basically, you don’t seem to lose anything and you gain quite a bit for that extra 20%. If it were me, I’d saddle up with that sexy D5000.