I am somewhat with the Craigslist crowd on this. Maybe eBay but shipping ca n be a bitch and a CRO could be damaged.
What people do not understand (maybe that is why the engineers over on SED don't want to pay new grads anythng ?) is that when you take a regular CRO down to very slow sweep speeds and then conect a battery to the test probe, even a five year old gains a certain appreciation for electricity. I have not see an DSO that can duplcate that, but I am sure they could de velope o ne if they got their eyes off of having the most useless features. And for a beginner, having a spectrum analyzer is useless, plus from what I hear ma ny of them are linear scale. Without accurately depicting the octaves, what good are they ?
It might be a good idea to just go look for electronic surplus, and don't e ven look for a scope that is in pristeen condition. Learn to fix it and cal ibrate it by the seat of your pants so to speak. There should be places lik e HGR and ESI all over the place. It is just a matter of looking at the ite m description. Mainly you want it to have a trace, both channels. you need the vertical positioning controls to work, on both channels. that will pret ty much clear any unobtainium ICs and whatnot in there. If it does not pass those tests then keep the mohey down. Offer like twenty bucks.
It is always best to go see the unit. some people are paranoid to go to str angers' houses but come on, if you are about to get robbed usually the deal is too good to be true. When you are around $50 or whatever, it is not a s etup. And if you think it is, take a gun.
Take a paper clip or something to hit the V input on it and see if you can get that "hum" waveform, if so, that much the better. You should be able to synch into that. Watch the controls, like "synch source" for example. Do n ot poke the paper clip into the BNC connector, it will make it loose and it might be in a predicament that makes it very hard to change. Just hold it at the outside and make the electrical connection.
If you get that 60 Hz waveform and the scope will synch into it you are way over halfway there. Sure, there could be alot wrong with it but that is a different thing. When they are dead, or have no trace or whatever, that is when you really don't want to sink alot of money onto it.
I have three lower bandwidth scopes but I can't afford to be giving shit aw ay. I might be able to hook you up with something in the mid range of CROs, my buddy has a couple of Teks around. One actually you can probably get re asonable is like a 465 or something, but it is a B or whatever, a bit rare. I think it moight have a hair more bandwidth. But it is supposed to have d ual time base and that part is not working. I ran the problem down to the t riggering (or retriggring) and kinda got lost there. But it works fine as a normal scope. Not sure what he wants for it but if you RSVP here I will as k.
Bottom line, the CRO is boss. I would consider a digital if they would make one actually REALLY emulate a CRO. All you digital scope folks, this is yo ur chance to get a convert. Other than that, I am a CRO afficianado.