I am building a keyboard. I designed a layout, and I don't believe it matches any keyboards out there. A USA-standard (ANSI?) 104-key set would fill most of my needs, but I still need a few other keys, most notably a pair of 2.75x or 3x keys for the bottom row (instead of a spacebar).
So, how easy would it be to find spares that would match a set I get elsewhere? I see cheap 104-key sets on eBay for ~$30, would I be able to find two more 2.75x or 3x keys?