What do you have to compare against? Weight is a relative concept. What have you ridden before?
If you're looking for a steel frame under $300, just get a Kilo TT/Stripper frameset and be happy. Most people will point you in that direction. There aren't too many other options if you're looking for just a frameset. If you want to truly go light, you can try to find a used aluminum frameset off of CL. Expect to pay at LEAST $300 for a decent-condition reputable aluminum track frame.