There are no motels really close to the NCAR Mesa lab.
Here’s a list of some of the more affordable and best ranked options.
The Quality Inn and Suites, Boulder (Sun Oct 25-Wed Oct 28: 3 nites: ~ $400)
ranked #1 out of 21 hotels on Trip Advisor
The Best Western Golden Buff Lodge (Sun Oct 25 - Wed Oct 28: 3 nites: ~ $250)
ranked #7 out of 21 hotels on Trip Advisor
The Days Inn on South Boulder Rd (Sun Oct 25 - Wed Oct 28: 3 nites: ~ $200)
ranked #8 out of 21 hotels on Trip Advisor
The Boulder Outlook Motel (Sun Oct 25 - Wed Oct 28: 3 nites: ~ $260)
ranked#12 out of 21 hotels on Trip Advisor
The Holiday Inn Express, Boulder (Sun Oct 25 - Wed Oct 28) 3 nites: ~ $400)
ranked#13 out of 21 hotels on Trip Advisor
The Millennium Harvest House (Sun Oct 25 - Wed Oct 28: 3 nites: ~ $475)
ranked #15 out of 21 hotels on Trip Advisor
The Rodeway Inn and Suites (formerly the Broker Inn) 3 nites: ~ $230
ranked #17 out of 21 hotels on Trip Advisor
The Best Western Boulder Inn (Sun Oct 25 - Wed Oct 28: 3 nites: ~ $300)
ranked #18 out of 21 hotels on Trip Advisor