[mumrah]

Under 100 for radio and TNC, sure. See the NinoTNC http://tarpn.net/t/nino-tnc/n9600a/n9600a_info.html. For radios we use second-hand commercial radios that we reprogram for Ham use.

However, coax and antenna can easily exceed 100 alone.

[mattbk1]

You can get started with pretty junky coax and a homemade antenna, although antenna parts that used to be common are sometimes now less-so. I spent part of my day visiting stores looking for twinlead or ladderline and found none.