You can find this one Morning Industry Brass Remote-Controlled Keyless Entry Knob, at Home Depot for $112.00.
Never worry about losing keys or
fumbling around with door locks again
with the Morning Industries Brass
Remote-Controlled Keyless Entry Knob.
This door knob utilizes
radio-frequency technology to open and
comes with a pair of remote controls
that fit conveniently on key chains.
- Keyless door lock allows remote-control entry
- Brass finish
- Supports usage with up to 15 different remote controls
- Auto-lock function re-locks the knob automatically 10 seconds after
- Anti-scan code-hopping technology prevents intruders from hacking into
the lock's radio frequency
- Distinct audible tones provide notifications for locking, unlocking,
jams and low battery
- Installation involves no wiring
- Includes 2 keychain remote controls, 2 keys for emergency use and
an adjustable backset
- MFG Brand Name : Morning Industry
- MFG Model # : 51891
- MFG Part # : 51891
This seems to be exactly what you are looking for. The installation does not seem to be any more difficult than the installation of a traditional lock, so it should be a very DIY friendly project.
NOTICE: I have never used this product, so I can not encourage nor endorse it's use. Use at your own risk.