Not including switches and keycaps, two cheapinos would come to around $60 according to the prices listed on its GitHub (I don't think I'd be confident to do the job myself, but going half with someone might be a cheap option).
This is the thread where I learned about the cheapino and the OP is asking a similar question that might have relevance to your situation https://www.reddit.com/r/ErgoMechKeyboards/comments/16id57p/recommendations_for_cheap_split_ergo_keyboard/