I have developed 2 parcels of land in a small town and had intended to build out and sell, but I have recently had a good offer for these parcels. I want to accept it, but I have never sold lands that I have developed in the past, always opting to build and sell instead, so I'm a little worried because I am not sure what to be wary of in this situation. I have the PSA and don't know what to do or what to watch out for. If I accept, the land will be tied up for 3 months and if it doesn't end up going through then it will be very costly for me. Any advice is much appreciated!

I think you weight the pros and cons. 

Does it still make sense for you to develop

You can try and shorten the due diligence period from 90 to 60 or 45 so it doesn't hurt you financially as much

Seems like you are unsure if the value of the lands at the moment

PM me if you need further help