I don't understand how aquasoil is 3x the price of other substrates...after shipping maybe 1 9L bag will be about 30 dollars. If you get a bag of florabase on dr foster's and smith for 20 dollars, it will also cost about $30 after shipping. For some people that get bargains on flourite and such it will be more expensive.
Even if you are just using aquasoil alone I think it will be better then some (can't say most until I use it) substrates available in the US, and it can be re-used many times also if done properly. I paid 23 dollars for a bag of florabase and it is crap...it has started to decay on me and turn to mush. Nobody needs a 18L bag of powersand, that is probably enough for a 200 gallon aquarium. For a 20-30 gallon tank you only need 2L and you can probably make your own with some peat, substrate ferts. and pumice. You don't have to use sand, power sand, and aquasoil. The sand in the front is purely decorative if you want a sand foreground, if I was going to grow plants in the foreground there is no point to use sand there. I have seen people that have success with just aquasoil as their entire substrate. Shipping will be expensive, but I don't think it will be that bad UPS ground.
Some of the other products are really expensive and you are paying for quality, and then there are other products that would just be a waste of money to buy, and then there are other products where the whole purpose is just for them to look pretty like the co2 check valve. There is always automatically so much hate, I think some people may be pleasantly surprised by some of their products.