How much would a junk yard pay for my car?
While most junkyards pay based on weight, depending on the type of car, it could have more value for the parts, in which case you could get upwards of $500 for the junker. Your best case scenario is if you go to different locations and check. Also try listing it on ebay, since many times car enthusiasts tend to buy junkers for the parts.
Different junk yards and auto-salvage yards may quote different prices for the vehicle. It would be better to look out on their online portals and make a quick comparison between those which you feel are the best. My friend had a 1983 Datsun which he got rid of for around $600 including a receipt via a used auto parts portal which collaborates with around 30 auto salvage across the country.