Nowadays Sound Chips in motherboards are most likely good. In my experience cheap soundcards are worse. I think a logical step would be something external, like a Schiit Fulla, even though it is over budget. But for your budget I think the limiting factor is not the sound chip of the Mainboard.

But my guess is, that there is some weird kind of audio “enhancement” going in. My dell work laptop has a feature on by default, which should enhance call quality, but actually makes everything sound as you were sitting in a bathtub. Please check both the settings in your audio driver and in your windows control panel. There might be a checkbox checked that you don’t want. I suggest disabling everything which suggest enhancing something or especially room simulation.