I wish I could say the same about SealSkinz.
Let me say first of all that I regard waterproof socks as an absolute necessity for my multiple-day walks in soggy Snowdonia (until I get some GTX boots, that is) when after just the first day my boots are absolutely sodden. Without SealSkinz the socks I wear (meraklon inner, loopstitch wool outer) are permanently wet and my feet become white and wrinkly.
My first pair of Sealskinz were bought in September 2001 and lasted 5 trips @ 1 trip a year (I only wear them for backpacking and not for day walks).
My 2nd pair were bought in August 2007, these were much better, they lasted for 11 trips (1 and 2 trips a year).
The 3rd pair were bought in April 2016 and one of them leaked on only the 2nd trip.
My current pair were bought in April 2017 and have had 1 use to date, when conditions were bone dry. Fingers crossed for the next time!
Given the cost of them, which I find is a lot on my limited income, they have a very short life, but I regard them as a necessity and I can't do without them. The life might vary with the individual and have a lot to do with the fit of your boots, your gait, the terrain and the load carried. I wear mine over a thinnish pair of synthetic material walking socks (Brasher Hillwalker).
To return to the OP's question, I don't think there are any "cheapish" waterproof socks. I've seen one or two other makes on Amazon, mostly a bit dearer than SealSkinz, but the user reviews for them are no better, otherwise I would give them a try.