Sort the climbing grades
Python 2, 58 54 bytes



lambda x:sorted(x,key=lambda y,B10=0:eval(y[1:]+'10'))


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How it works

y         y[1:]+'10'   eval(y[1:]+'10')
=======================================
VB        B10          0  (a variable we defined)
V0        010          8  (an octal literal)
V0+       0+10         10
V1        110          110
V2        210          210
...       ...          ...
V17       1710         1710