I have been doing this stuff for over 45 years. Please let me give you a few tips to keep with you for the future. The first mistake you made was insulting both the seller and the listing agent, especially the agent. He is the one who helped them pick the price!! With your offer, you make him look stupid.
In CA, every listing agent with more than a year in the business has buyers for each property, at a given price. Do you really think that if the sellers were willing to drop their price $30K to $40K, that the listing agent would not be the first to know and that you would be close to the last to know!
The reason you have an agent is to help you make your way in this industry. Your agent should have contacted the listing agent and said he has a real buyer, not a lowballer. Then they talk about the seller's motivation. Maybe one of the heirs has a hair up the butt for a certain net price. That is what you need to know before you waste everybody's time. The listing agent cannot and will not tell you a price below asking, but he can advise your broker what not to do.
I have bought hundreds of properties over the years and never have I paid less than 90% of the asking price. My point of view is to find my value in that specific property. If I did not have a great upside, either this year or next, or a development deal to make it increase in value, I would not buy it.
I once bought a parking lot for a Pick & Save store that was a separate parcel. I had it rezoned to R from C and built 30 condos. I paid the asking price of $100,000. It was a bit of a risk, but the per door price of $3300 in Los Angeles was a deal. You need to find you backside value before you make an offer. You have to decide how much profit you will accept on every deal before you buy it.
The other issue you have is to find a better team of remodelers. $40,000 is a hell of a lot of work on a single family. Go to Home Depot and take some classes on repairs and meet some of their contactors. They may not be the lowest priced, but at least you can get some real prices. You need to know in your head what a paint job will cost for a certain size home, what flooring is per square foot, what it will cost to replace a bath and a kitchen. Stop watching that flip crap on TV and get out into the street and find your own contractors and prices.
Sorry to be short and cranky, but I am old so it is OK. Best of luck on your adventure.