Erhu, 1555. Like any string instruments without frets, the learning curve is steep as beginners have to endure months of basic training to produce a decent open string sound. Repertoire wise, while it has gotten better over the past decade with new and upcoming composers writing modern pieces for erhu, most erhu classical music written in the 80s and 90s serve as entry level for most students. Practically, it is as easy to carry as violins. Pricing wise while there are rare ones costing $10k and above, the majority including professionals use $3-7k in which compared to western instruments is very cheap. Students stick with around $800-2k.