You can easily find a very nice analog scope for under $75-100 in good working order, used. These days you should be able to do much better than that, even. (Outside of ebay - which adds some overhead - $20 seems fairly common for decent quality dual trace analog scopes from the 80s and early 90s)
Dont get anything older than that - The major brands of the 90s in particular, workhorse scopes made for schools and basic working lab scopes are often very good buys.
Just don't jump on the first one you see.
Try to get one without unobtainium parts - ask here - whose service manual is also online, thats listed as working, not 'for parts or not working', so you wont get somebody else's headache.
Watch Dave's segment on getting your own old analog scope. Its all very good advice.