I love these pens and these are the lowest I can find them for even without the extra discounts below.
With Tesco's offer of spend over £5 get £1 off automatically (no code needed):
So if bought two = £4 x 2 = £8 - £1 = £7
divide by two that makes it £3.50 each!
You can also get a further £1 off £5 using promo code TD-YN9J if you haven't already used it.
Which makes them £3 each if bought two!
Free Click and Collect!
The best part of this is that they're widely available and not just for specific stores.
Thanks to Chanchi32 for the heads up on the tesco stationary deal!