Typical price for an NSX oil change is $20-30 with conventional oil, $40-60 with synthetic oil.
If you take it some place (like your dealer) where they don't stock synthetic in the recommended 10W30, they might let you bring your own oil and change it for you.
Also, the oil change takes 5.2 quarts. Most places will let you take the extra 0.8 quart with you to use for next time (but many places will just forget to give it to you if you don't ask about it). Bring a gallon ziplock plastic bag with you to put the oil container in, as it may be greasy.