In response to your concern about contractors low balling- the contract you sign with them is to protect both parties, the contract should state the scope of work to be done and the amount you will be charged with a cap on additional expenses for contingencies.
I'm at the Baird & Warner office on Central Street in Evanston, you should stop by and we can talk. I will be happy to gather facts for you and review them with you to help you make an informed decision.
Baird & Warner
2926 Central Street
Evanston, IL 60201
773 677 5340
My first question is IF you update for a cost of 70K, then how much would that increase the value of your home? 100K? 130K? The Return of Investment is key to any improvement. Also, timelines for the need to sell would need to be addressed.
So many other questions need addressing before you can make your final decision.
Remember dirt over time increases in value and homes depreciate. So if you have a bigger lot in a desirable area make sure to do all your due diligent.