Our club put in two new center pads for our carrier circle a few years ago, a 6 foot pad and 9 foot diameter pad, and total cost of the Quick-Crete, mixer rental and such came to about $500 all in and the club did the work. We put these right on top of the old ones that had sunk into the ground so they had a good base already and just tossed in any kind of wire mesh anyone could find for re-enforcement. I'm guessing that if they have them professionally done it would be about $1000 to $1500 per pad. I would make the pads as large as practical. Maybe 8 to 9 feet diameter to allow for some room to step back, and 4" thick. Make them slightly above grade and back fill up to the edge to remove trip hazard, and make them have a slight crown to them so they drain when it rains. Broom finish to prevent slipping when they do get wet. If they are gonna do it, do it right!
Type at you later,
Dan McEntee