The ecotech stuff works well.
And it's not expensive. Look at the volume printed on the bottle and then figure out how many of those little tubes of crazy gel you would have to buy to fill that bottle.
On Amazon, the big bottle of Ecotech Coral Glue is $55 for 295ml.
On Amazon, the .14oz (4.14ml) tube of crazy glue gel is $4.
You would need to purchase 71.25 tubes of crazy glue gel to fill that ecotech bottle, which would cost you a whopping $285.
Even if you got the same size tubes for $0.99, it would still cost you ~$70.
Side note: with any size bottle, I'd probably pick up an extra top or two since they can get clogged over time. I have the big bottle now, but next time I'll probably go with a couple smaller ones.