Seems like what you're looking for is more along the lines of a
consumer-level USB soundcard, rather than an audio interface. Creative X3 or thereabouts. The device to beat may still be the old X-Fi HD, long discontinued... Creative's modern DSP engine is a bit crappy and introduces high levels of 1/f noise for some reason. There may be USB sound dongles that are decent enough but it's a crapshoot.
It should be possible to make a USB audio interface work, but you basically need one that is good in instrument input mode (which most closely resembles a consumer line-in), generally with switched mic/line/inst or XLR mic + TRS line/inst, and a lot of them would require custom-made output cabling (typically
RaneNote 110 #10B) unless you get a model with RCA jacks already built-in, like a MOTU M2 (which however would be twice the budget).