If you know that the company is worth more than what you are being offered, then don’t feel obligated to significantly lower your expectations.
If you have a serious buyer, he/she/it will wish to see the financial information over the past few years and a list of assets and liabilities. If you show that the company is profitable (or has a demonstrable potential to be profitable) and what it is really worth, the buyer will likely be willing to negotiate on price.
The only time where you might choose to sell before getting an appropriate offer would be if your operating costs are bankrupting you and you just can’t afford to carry on. Sometimes it is necessary to cut your losses and move on.
If you are having trouble deciding what to do, you have support people you can speak to. Your accountant and lawyer can tell you whether an offer seems sufficient for what you are selling.