Trapani to Segesta and back by taxi?

[YoHoHo]

I wrote a far too long post (as I sadly do) but will save that for later. First comes down to a more simple question I hope someone here can help me with.

 

Sep. 1 we will be docking in Trapani. Want to visit Erice and Segesta.

 

I am not sure of taxi cost to get to Segesta (seen huge range of prices - have emailed for a quote but the pre-book sites I have seen promote they have lux cars and I really only want transportation so maybe they are too expensive). 

 

Midday we could take the bus ( http://www.tarantolacuffaro.it ) up at a suitable time but the next (& only) return is too soon (1.5 hours) and thinking we would like 2 hours. 

 

My immediate questions are:

1. Is it possible (reasonable to assume) there will be a taxi at Segesta available to take us back?

 

2. Any thoughts on cost? one-way, or both ways with a wait (or would they just leave and return at a agreed upon time)