Petsmart is carrying the ZooMed Hydroton balls, or LECA, Aliflor, etc. for 9.99 for approx 4 qt. right now, that seems like the cheapest source, without waiting for a reptile show. I don't remember reptile show prices, since I wasn't in the market for LECA when I last went.
Including shipping to 08753, I'd be looking for a source charging less than 9.99 per 4 dry quarts. Any sources????
Look for a local hydroponics store, call and ask what type of LECA they carry. I used to get aliflor from a local orchid supplier but when she closed I had to start getting Hydroton from a local hydroponics store. Make sure you compare prices for the different sized bags too! Here, a small bag costs $14 but a large bag (5x the amount) only costs $38...do the math
$10 for around 4 quarts seems like a reasonable price. If we assume that's really 4 liters, that's $2.50 per liter.
If I charged that much for PrimeAgra - the only brands of LECA made specifically for horticulture, rather than be remarketed from concrete production - my standard box would be $56.25, rather than the $23 I actually sell it for.