Welcome and thanks for your question!
First, in order for a C Corp NOL to carry over after a sale of the business, the sale needs to be structured as a stock sale rather than an asset sale. Stock sales are less attractive to potential buyers because an asset sale helps shield them from liability related to any debts, lawsuits, etc that occurred before they purchased the business.
Let's assume the sale was structured as a stock sale. While the buyer would be allowed to deduct some of the loss, under IRS Code Section 382
, the loss is limited. When there is a more than a 50% change in ownership in a "loss corporation" (generally, a corp with an NOL carryforward), the loss is limited to the value of the corporation at the time of sale times the "tax-exempt rate." The tax exempt rate refers to the long-term applicable federal rate (interest rate published by IRS). The applicable federal rate is currently about 2.6%.
For example, let's say the value of the company is $150,000. $150,000 times 2.6% is $3900. That means in any given year, the buyer could only deduct $3,900 in your NOLs to offset their income. That's not that much of an incentive.
In regards to the value of the company, you need some meaningful method of determining the value. Here is a really good article
about the different methods available. The most common method I see is some type of multiplier, e.g. 2 times net income. What multiplier or valuation method is most appropriate is dependent on the type of business and risk your buyer is assuming.
If you need any clarification, please let me know and I will gladly assist you. If this satisfactorily answers your question, please give the answer a positive rating. Thanks and have a great evening!