prices are going to be the same anywhere you go,minor fluctuations in price,but generally the same.Now...here's what to ask and what to do -
stripping old paint - make sure its done with a carbide wheel paint stripper,NOT HARD SANDED and NOT WATER BLASTED,this will ruin your bottom resulting in massive amounts of blisters and water penetration.
Paint - depending on how long she sits in the water or is trailered, use Co-polymer ablative,it will withstand periods out of the water without failure as opposed to a anti-foul with algisides which becomes useless after being out of the water for any prolonged period of time.
WATCH THEM PAINT THE BOAT- many marinas will charge for top-of-the-line antifoul and will slap on one coat of cheap paint...make sure its Interlux-Petit or System3 - anything else is crap.
READ THIS -
http://www.yachtpaint.com/usa/boat_painting_guide/pdf/antifouling/intro.pdf