Someone nearby appears to be selling a Dark Initiate LE v4 with possibly a mid-grade blade and a yellow LED. Seller says it's 5 years old and is asking for $100. No sound, standard button. I believe the base price for this model is $80, so what would be a reasonable counter-offer for me to make?
Well, that's kind of a pickle. On the one hand you could easily say just that "online I could order the same thing right now and get it brand new for $20 cheaper than you're asking, so drop it to $70 and if it's in good condition I'm thinking that might be more fair/tempting." Since you're getting a discount and they are still recouping profit on something they probably got some enjoyment and use out of. Not to mention that if they did use it, you have no idea how much that blade has gone through, or if they kept it "safe" till you see it. It could be all kinds of scuffed up or whatnot so I'd want recent pictures before committing anyway.
On the other hand it's a reality that the economy isn't great right now and things are hard for many, so they may be selling it out of necessity more than desire... if this is the case that could be why they rounded the price up more so than "getting over" on an uninformed individual. Heck maybe a little bit of both? So idk, I wouldn't let compassion blind you, but also try not to be ignorant of their potential plight from a negotiation/haggling standpoint if they are resolute and refuse to budge on their price.
So yeah, I'd call $70 fair-ish for both parties, and $60 more a "great deal" for you that'd be "hard to resist. But of course that's just my take on it. Best of luck, and may the Force serve you well. If in doubt use a mind trick and say "you will hand me the lightsaber and return home happily" with that classic hand wave. But I suppose that's the more acceptable of the Sith options...