Can't speak to the lens specifically, but I'd not go that route or expense unless the kid is truly passionate about his efforts.
Only raised one son, and he frequently made requests where interest died on the vine after a week or so.
If he is dedicated, however, then the price is not unreasonable for quality glass.
Google up " Sony FE 70-300mm SEL70300G F4.5-5.6 G OSS' plus the word "review", and one should find plenty of evaluations on the web.
If he is shooting a crop sensor camera, then one is essentially buying a 150 to 450 or 160 to 480 mm piece of glass which can be quite adequate for wildlife. Google up his camera model to answer that question.
Most professional and serious hobby folks tend toward the Nikon and Canon brands as they have almost unlimited selections for lenses.
Last edited by 1minute; 11/29/18.
