G'day,
the reference 7100 Sea Hawk models go back quite a bit.
These were introduced in 1989 as an extension to GP´s then popular "GP 7000" line, which almost all came with ETA-based movements:
I like these ref. 7100 Sea Hawks quite a bit; nice, comfortable watches not extremely large and very easy to wear.
As per the price, it´s all depending on the condition and the willingness of a single customer to pay a given price; we don´t do appraisals and don´t discuss prices, but i don´t think the amount in question is unfair.
This includes one downside, which is the age: the relatively low individual number point at an age of fairly more than 10 years. This suggests to have it checked by GP Service, if such has not been done in the past 5 years.
Cheers,
Peter