I've played at the Caguas paintball field, they're a bit more cheaper than Roberto Clemente but they only have 2 fields: 1inflatables and 1 speedball. Roberto Clemente has: 1inflatables, 1speedball and 1jungle.
They're very safe, always check for barrel plugs, mask and enforce their rules.
They have 3 fields: inflatables (I've never seen up, but I've been told they take them up during the weekends), Jungle and Speedball. They have fair prices: 15$ entries with unlimited co2 refills; 25$ for entire, rented gun, rented mask and 100paintballs (refills also); they have an assortment of paint balls ranged from 45-50$ 2000 ball boxes, 30$ for 1000balls and 20$ for 500. During the week (Mon-Friday) you can organize groups of 10ppl or more and they'll open up the park for your group with all the services(except inflatables) . Saturdays and Sundays are the most filled days, thats when they're open and all the services are up. The refs are good and fair, they're helpfull and will answer any questions or doubts you may have.