The nice thing about wanting a ss amp for a low impedance phone is that one of the main problems in phone and amp matching (impedance mismatch) is taken out of the equation, so any SS phone amp will work and the question becomes synergy.
Below your price, I would say take a look at the EC/SS by eddie current, maybe the shanling ph100, and the kicas amp for commercial pickings. Gilmore lite also. There may be a couple more, but those three are pretty good amps for the money. That said, your best bang for the buck will come with DIY, if you are willing to go that route. There are several DIY amps in your range which are very good. One is the CK2III, the amp that I am running at the moment. $200 and very good with grados.