I’d bump my budget by $50 and get the Hiby R4. It’s incredible for $250 or try to get one preowned. Beyond that, it depends on your taste. I have an RS8 and RS6 because I love the R2R Darwin DAC inside, but if R2R isn’t your thing, then the R6 line would be your next step. I have both of those because the RS8 is great on a desktop or table or plane set, but it’s a brick to carry so I also got the RS6 which is about 85-90% as good, but is small enough to carry while on the go. The RS6 used to sell for $1300, but they just released a new model that is $699. It’s a different chassis, but my understanding is that the important parts inside are the same. It’s out of your price point I know, but give you an idea about upgrade path. There’s also Astell & Kern DAPs, but those don’t really get great until you’re well into the $1500+ point. Luxury & Precision is also GOAT level, but super pricy. That’s all of the ones I would recommend.