At Celestial Memories by Orbitpics, we use high quality balloons which will not harm the environment, and the burst balloon particles fall gently to the earth and biodegrade, roughly at the same rate as oak leaves. 
We do not scatter human cremains, but are willing to launch and photograph them inside clear sealed ornaments, to be returned to you afterwards.

Prices for launching a keepsake into near space begin at $1800 Canadian and may vary depending on the weight and size of the object. 
400 grams or less is priced at  $1800 CDN
800 grams to 1 kg is priced at $2200 CDN
1 kg to 1.4 kg is $2600 CDN