Be gentle as this is my first post.
Argos are doing a 20KG Dumbbell set by York for 22.99 - I've been looking for a set over the last month and this is the cheapest 20KG cast iron set I've seen, and a quality name too.
Also has 81 reviews at 4 1/2 stars out of 5.
Available both Instore and Online.
Note: Item is NOT as pictured on Argos site. Changed locking nuts to hard plastic and added a rubberised grip to each handle.