These things don't go on sale.
If you can't swing $40 you need to budget for a long term goal.
What is your motivation for lower cost? What is your goal? Single player fight stick? Desktop control panel? Bartop? Pedestal Cab? Full size 4 player upright? If you don't have an answer for this, Vigolix is your answer. What are your favorite games?
KADE / AVRs are the new custom keyboard hack for the ages. I don't quite recall when keyboard encoders came on the scene, but oh man, if we had IPACs, KADES and Keywhizs back then, BYOAC would have been a totally different landscape.