I have started to build a fairly large new layout which has points too widely distributed to make manual operation easy, but upon looking at off the shelf point motors I couldn't really justify the price.
After playing around with a number of options I decided the most cost effective solution was a servo modified to work as a DC motor with stop switches.

The components are dead simple, just two micro switches, a power supply, the servo and a double pole double throw (DPDT) switch to control it.
total cost is somewhere in the region of £1.50 if bits are sourced from ebay. Servo £1, toggle about 20p, 10p each for micro switches and another 10p ish for other bits, wires plastic etc.

The first thing to do is modify the servo:
bypass the electronics so it is simply a DC motor with a gear box, this is just a case of chopping off the power and signal leads and soldering the power leads straight to the motor.
The other thing I did to make thing a little more simple was to remove the lugs on the bottom of the gear which prevent the servo from rotating continuously.

This isn't really needed but it means you don't have to worry about alignment later.

I then whipped up a proof of concept.

This worked nicely so I started mocking up the structure for an integrated design.

And put together a prototype, as per usual with me the plastic bits were made on silhouette,

The motor is arranged vertically immediately below the point, with a pivot and a 0.5mm brass rod as the lever, there is a plastic tube over the section between the servo control arm and pivot to stiffen the arrangement, the tube is deliberately oversized to allow the rod to bend along more of its length which should hopefully improve it's life.

[yt]