Working From Home Resources/Microphone Recommendations
You can get surprisingly far with even a potato mic, as long as you use it properly. A proper one will always help, though. On this page you'll find recommendations for microphones in every price range.
When looking at a mic, make sure you take a careful look at its connectivity - if it has USB you'll be good to just plug it into your laptop, if it has only XLR you'll need an external audio interface as well. Most of the mics on this page will be USB unless otherwise indicated.
Where To Buy
A good place to start will be Amazon, bearing in mind that they are prioritising essentials and so delivery times may be quite long indeed.
If you're in the UK take a look at Gear4Music, if in continental Europe look on Thomann (they also ship to the UK, however it can get a bit costly).
Do not underestimate eBay, provided you are willing to shop around and investigate the quality of the gear you're purchasing, you can get very good deals with much shorter shipping times compared to normal shopfronts with the current climate.
Budget Zero
You'd be surprised how good an earphone (e.g. EarPod) mic can sound, if you use it properly. TODO what does properly mean?
<£40
Samson Go TODO
<£75
Samson Meteor TODO
You'll see a lot of YouTubers and streamers using Blue Snowballs, and while they're fine, if you can stretch the budget for a Meteor it'll sound much nicer for radio, so the Snowball is not recommended.