I paid $47 for this vitamin D test (via blood draw): https://www.lifeextension.com/lab-testing/itemlc081950/vitam... You get a doctor's prescription (from a Florida doctor, good for anywhere in the country) and instructions to go to your nearest Labcorp for a blood draw. So make sure you have a Labcorp near you.

Here are a few alternatives you can look into, mentioned in this discussion: https://news.ycombinator.com/item?id=15868143

[0]: https://www.privatemdlabs.com

[1]: http://www.directlabs.com/

[2]: https://www.walkinlab.com/

[3]: https://www.health-tests-direct.com/

[4]: https://www.personalabs.com/