You could change it to a drop bar setup for under $350. Much would need to be used instead of new.
I dont think you could change to drop bar 1x11 for $350.
You will need-
- an 11 speed compatible wheelset
- 1x11 shifting
- drop bars
- bar tape
- new crankset
- new chain
- new cassette
- new cables and housing
- new brakes(mini v or cantilever)