whoa glitchy system
Hi, are you interested in the bike?
yes. but it's kinda pricey for a 27 yr old bike. 
I know, but this is a collector's bike.  So people generally fix them up and only ride the bike to show off.  It's actually worth quite a bit because it is so old, yet in decent condition.
needing a handbrake isn't in a decent condition. tell you what. i'll give you 100 for it. 
How about if I throw in a hand brake and you can install it yourself for $150?
yeah that's not gonna work for me. 110 is the max i'd pay for a bike in this condition
Is there something else I can throw in to sweeten the deal?
nah. 110, bike and the handbrake. if that's ok we got a deal 
Okay deal.