The Collected Stories of Arthur C Clarke - £1.99 at Amazon UK.
I've been waiting to see a reduction on this for ages and it's suddenly plummeted. 104 short stories in total.
Here's the entry for the print edition at
isfdb.org
The Day of the Triffids - John Wyndham.
A Kindle Daily Deal - just 99p, again from Amazon UK. From reading a few comments, it looks like there could be an issue with the font size, so maybe not for everyone unless you like tinkering with settings and formatting.
That said, it's one of the all-time classics of British science fiction, so I'd recommend giving it a go and possibly learning how to manipulate a few more functions on your ereader if necessary.