I feel for the OP. Being a lefty sucks for single bevel knives. Paying 40-50% extra for being better than everyone else is hard to take. I bought a lefty usuba a while ago which was dear as hell, could have pretty much bought any well-known maker I wanted but I bought a less-well known one and paid through the nose.
Keiichi at BluewayJapan has a few lefty usubas and yanagis but I'm not sure if they're what you're looking for, they are pretty cheap. If I were you I'd try a Watanabe maybe if you're gonna get a new one. Wouldn't be cheap, but not as expensive as others about