What is the delta v required to place a satellite in L2 from earth transfer orbit ( Like the James Webb Telescope )? Does orbits closer to L2 different delta v from orbits far from L2?
Getting from LEO to Earth-Sun L2
Departure: 3.23km/s Arrival: 0.9km/s
Note that this is to the actual L2 point.
Second part of your question..
To match a Halo orbit around L2 such as the JWST uses, would require a small amount more departure delta-v, and very very little (<50m/s) of arrival delta-v.
The JWST will actually not slow down when it gets near its Halo Orbit, but will speed up by another tiny bit, to insert itself into the orbit.