Python 2, 172 147 128 117 112 bytes

lambda w:ord('8%\x1806(*D\x0e0t0\x1d'[sum(map(ord,w.replace(*'gM')))%77%24%13])*(2+('/'in w))*(4-('g'in w))/160.

Try it online!

Alternative:

Python 2, 112 bytes

lambda w:ord('00T000\x88::000000Pl\x1c00p\xe8JJ00'[sum(map(ord,w))%360%103%26])*(2+('/'in w))*(4-('g'in w))/320.

Try it online!

• -5 bytes, thanks to ovs

Python 2, 172 147 128 117 112 99 bytes

lambda w:ord('8%06(*D0t0'[sum(map(ord,w.strip('g')))%77%24%13])*(2+('/'in w))*(4-('g'in w))/160.

Try it online!

• -5 bytes, thanks to ovs
• -13 bytes, thanks to Lynn

Alternative:

Python 2, 112 bytes

lambda w:ord('00T000\x88::000000Pl\x1c00p\xe8JJ00'[sum(map(ord,w))%360%103%26])*(2+('/'in w))*(4-('g'in w))/320.

Try it online!

Python 2, 172 147 128 117 bytes

lambda w:ord('8%\x1806(*D\x0e0t0\x1d'[sum(map(ord,w[:(w+'g').find('g')]))%77%24%13])*(2+('/'in w))*(4-('g'in w))/160.

Try it online!

Python 2, 172 147 128 117 112 bytes

lambda w:ord('8%\x1806(*D\x0e0t0\x1d'[sum(map(ord,w.replace(*'gM')))%77%24%13])*(2+('/'in w))*(4-('g'in w))/160.

Try it online!

Saved

• -5 bytes, thanks to ovs