The most I've seen them for is $2.50. Some LFS might take advantage of their effectiveness, but it is testament to how well they deal with nuisance algae for people.
For this area, SnowManSnow, that's expensive. At some times of the year it's hard to get/ship Mexican Turbos and I've seen them go for $6 each elsewhere... but because of their scarcity I don't even try to get them in during the hot season - they don't ship well and there's a lot of mortality -- hence the high retail price.
At this time of year, though they should be readily available. Just comparison shop.
I wonder if Jenn has any in her shop.. may be visiting this weekend for an ocean light anyhow (according how the butter up dinner with the wife goes haha).... nah...take her out anyhow
I usually see them in the LFS for 1.99 to 2.99. Since they are the only vegetarian snail (other than conch) that eats anything beside film algae, they are well worth it.
Nice stuff, I got mostly trochus which, IMO, do better than Turbos. The Mexicans die fairly fast in our warmer systems. Trochus are pretty agile, can get up if they fall down, and don't bulldoze.