Nikon 18- 105mm afs vr can get the cheap 1k5, probably.

Pentax's weakness is fixed focus and automatic pan/tilt, and low-grade vacancy. The cheapest ones are FA FA 50 1.4, F 50 1.7+0.7. They are all around 2 K, and then go up, P's family has a rich set of famous mirrors, three princesses and three biscuits ... not much to say.

The problem with Nikon D3000 is that it doesn't have a body motor, so it must automatically get the afs focusing head. Actually, it's not cheaper than Pentax. Af-s 50 1.4 also gets 1k5. If it's a D90, it's best on an autofocus lens. Oh, by the way, there are also 35 1.5K nearby.

As for the manual lens group, Nikon does not mention it. Among all the fuselage, Nikon has the longest distance, the most troublesome port change and the least re-export. There are many old men in P's direct PK, and M42 automatic metering is supported, all of which can realize trap focusing (M42 needs to twist a piece of aluminum foil paper on the lens butt). (PS: What trap focusing can Nikon achieve on the Internet? To know what trap focusing is, please search Pentax trap focusing. With trap focusing, manual pan/tilt can also capture a picture, which is no slower than automatic pan/tilt. If you have any doubts about this statement, you can find a place to test the machine.

There will be many fixed-focus options for entry, such as Ricoh below 200, Phoenix, Huaguang, Russian helios around 300, Yaka at 600- 100, Pentax, Zeiss, Meyer, Pantaikang and so on.

As for other lenses, such as telephoto, Pentax's 55-300 DAL 1k3 and Nikon's AFS 70-300K5 are taken. You refused. My Nikon has a 70 -3001k. Sorry, the D3000 has no body motor. Please operate it manually.

D3000 is cheaper than other Nikon machines now, but it will be returned on lens anti-shake and lens motor sooner or later.

I have never used a Sony machine. If these two machines are compared, I recommend you Pentax.