Here in Washington State, it's $4/year more for a Real ID driver's license than for a non-Real ID license, and licenses are good for 6 years.
A passport card is $30 and is good for 10 years, so effectively $3/year.
Passport card vs Real ID license cost is interesting. Going for the passport card is more expensive for the first 6 years, but then for years 7-10 the passport card wins. For years 11 and 12 the Real ID license again wins. And then for years 13 onward the passport card wins.
However, the assumes you already have a valid passport or passport card. If you do not, so this will be a new one rather than a renewal, there is an additional $35 fee.
If you don't actually need a passport or passport card other than to use as a substitute for a Real ID license, that extra one time $35 fee makes quite a difference.
It makes the Real ID license come out ahead for years 1-18, then the passport card wins years 19 and 20, then it is back to the Real ID card being cheaper for years 21-36, then the Real ID license for years 41 and 42, and then finally the passport card from years 43 onward.
So, for Washington State residents, in summary:
• If you already have a passport, but don't want to use it for domestic travel or other things that a Real ID license can do that a regular license cannot, getting a passport card is a good deal.
• If you don't already have a passport, and so have to pay the extra first time $35 fee to get a passport card, then it is probably not worth it unless you actually need a passport for purposes other than being a Real ID substitute.
I can't find any site that lists the Real ID extra fees, if any, for driver's licenses in other states. Checking a couple of individual states it seems we are getting a bad deal here in Washington. It appears that there is no extra fee in California, New York, and Illinois, for example.
Given that either of these is going to involve some amount of driving, public transit, and/or hired cars, and the fact that you probably should have a passport anyway, and the fact that flights cost quite a bit, the 35 bucks should barely go noticed either way.
