Exit Advice from Founders

Selling bootstrapped startup (S Corp) 100% owned by one person. The buyer wants to do a stock deal - i.e., acquire 100% of the stock. But the Legal costs will be high.

Options include

1. Asset sale - sell code base

2. Exclusive license

3. Sell the stock.

The company is 5 years old.

What is the best tax option? Perhaps an empirical example.

Ps not a major amount - exit value - just $4m.

I want to get some good options before handing off over to law firm. Would like to ensure that legal fees are optimized.