I too ride a cheapo folding bike that I don't like throwing too much money at. I have
these inexpensive pedals. They seem ok and pretty rigid. They are spring loaded. You fold them by pressing them in towards the bike then flipping them down. the only downside is because I don't have a kick stand when I lay my bike on the ground on it's side the weight of the bike will fold the pedals so I have to make sure I check every time I get back on the bike.