Interesting. On the MTicket App, it says a trip to Providence from Hyde Park is $6.25. Idk what explains the discrepancy between your link and what I’m seeing on the app. Im inclined to believe the app though because the app actually sells the tickets.

That's not a direct trip. That $8.75 is $3.50 for a ticket from Hyde Park to Canton Junction, and $5.25 for a second ticket from Canton Junction to Providence. You were looking at a time when there were no trains that stopped at both Hyde Park and Providence.

A single Interzone 8 ticket is $6.25.

https://www.mbta.com/trip-planner?_utf8=%E2%9C%93&plan%5Bfrom%5D=Hyde+Park&plan%5Bfrom_latitude%5D=42.25503&plan%5Bfrom_longitude%5D=-71.125526&plan%5Bto%5D=Providence&plan%5Bto_latitude%5D=41.829293&plan%5Bto_longitude%5D=-71.413301&plan%5Btime%5D=depart&plan%5Bdate_time%5D%5Bhour%5D=11&plan%5Bdate_time%5D%5Bminute%5D=00&plan%5Bdate_time%5D%5Bam_pm%5D=PM&plan%5Bdate_time%5D%5Bmonth%5D=2&plan%5Bdate_time%5D%5Bday%5D=1&plan%5Bdate_time%5D%5Byear%5D=2023&plan%5Bmodes%5D%5Bsubway%5D=false&plan%5Bmodes%5D%5Bsubway%5D=true&plan%5Bmodes%5D%5Bcommuter_rail%5D=false&plan%5Bmodes%5D%5Bcommuter_rail%5D=true&plan%5Bmodes%5D%5Bbus%5D=false&plan%5Bmodes%5D%5Bbus%5D=true&plan%5Bmodes%5D%5Bferry%5D=false&plan%5Bmodes%5D%5Bferry%5D=true&plan%5Boptimize_for%5D=fewest_transfers#plan_result_focus