It's not too hard to do yourself
the challenge even for the pros is the clarity of the ice
and rate of melting would be another issue
over the years I have done a number of over the top ways to give out gifts.
One of my fav and most popular is freezing items inside ice.
the trick the pros use for crystal like ice
is while freezing you keep constant vibration to your mold
though they have expensive custom machines and set ups that are a bit more complex to detail here
but replicating the process at home can be done
provided you have the freezer space
I did come up with a floating rose (by magic) inside a glass dome you can buy from any hobby shop.
As an illusionist - I get asked to do this sort of thing all the time.
if you want to know more- PM me
the floating rose in the glass dome is pretty simple and cheap to do.
looks like magic (cause it is) and is always the subject for allot of conversation