There are several kinds out there. Actually, your question is quite old, did you find a solution for this? Nowadays, you can get the wireless A/V kind, which also allows you to monitor from the ground, but you can also get a small portable unit that will record to SD Card as a video or as time lapse JPEGs.
The A/V transmitter type costs about RM150 - RM200, image quality is like mediocre mobile phone camera level, and you will need an A/V recorder such as a video camcorder with the appropriate cabling on the ground. It is very susceptible to interference, so you will get a nice scratchy recording! I'll try to post images soon.
Oh, BTW, if you want to try the A/V recorder route, I have the whole setup if you want to borrow it to try.