The best price I can find on perlite is $8 for a 4 cu. ft. bag, that's
$54 per yard, plus shipping. I can get a truckload of sand, 15 cu.
yds., for about $85, delivered. I have very heavy clay soil, I
amended my garden with compost and sand, about 1 yd of sand per 100 sq
ft of garden, also I removed the heaviest, pure red clay altogether.
Had to work it all in real well, a process which will never be done.
Perlite may be better, but unless they start selling it in truckload
quantity, I think it is way too expensive a method when there are
alternatives. Sand plus clay plus compost plus backbreaking work
equals good garden soil.