I've had my eye on a Robinson M96 for a while.At my local gunshow there is a person selling one,asking price 1250. used but with box and papers. I offered him 1000 cash and he came back at 1150. I have made him the same offer for the last 5 shows/months and he does not budge. the difference is 150 which is keeping us from doing a deal. I think my cash offer is fair seeing the gun market is a little soft these days. he's held on to it for the last 5 months over 150 bucks. Should I move on and look for another Robinson or up my offer?

Swap Meet 101:  Always be ready to walk away.  This guy isn't that desperate to sell or else you wouldn't see him with this rifle for so long.  And the price isn't that good or he would have sold it to someone seeing as he has had it up for sale that long.

Go up a little if you want, but he oughtta start throwing in mags, ammo, sling, case, etc. etc.

Or start watching the auction boards.  Something will come along.

I have been in the same situation with cars a matter of a couple hundred bucks but some times it isn't the money just a matter of giving them the money. I would hold out, or make a little higher offer or walk away

Count out 10 $100 bills on his table and see if he may want to talk a little more.

You've made him the offer 5 times---I am sure that he thinks that you just "have to have it", etc. As has been suggested, it may be okay to go up some---even split the difference---and if that doesn't work, I'd be prone to walk away.  Another alternative----next time you see him----why don't you talk about something else or some other item-----don't even mention (or even look at) the item you are interested in----then, it might be very interesting to see what he does and/or says the next time you see him----he knows you want (or used to want) it----see if you can maneuver him into making the first "move".