I picked one up from Costco recently. Winix 2020U (korean brand) for around £140-£150. My son suffered from hayfever this year (first time ever) and affected his sleeping. No issues since getting it.
Just make sure it has a HEPA filter to capture all the pollen. In terms of tech, it's just a basic fan but features that are nice are night/silent mode, and easy to clean and get replacement filters.
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