Negotiating prices of potential property

[Nathan Nguyen]

I'm currently looking at a 4, possibly 5 bedroom property built in 1740s that can be used as a business space and part of the property can be made into a 2nd unit for rental. I like the location as it is close to other businesses and has a good amount of parking space. Its been on the market for more than a year and owners had just lowered price by 18K so its currently at 340K. I've not gone to look at it in person but from the pictures online and description, it appears that some renovations have been done to make it look new so it appears to be ready for move in but i'll have to check.

What are some of the methods/strategies you use to negotiate a lower price on a potential property? What are things you're looking out for when inspecting the property to leverage the negotiation? I've heard of recommendations to try to buy properties at 80% of listed prices which lowers my offer to 270K. Is this realistic?