Avoid excessive handling to maintain their condition
For pure investment purposes, be aware that this set had a large print run, which may moderate long-term appreciation compared to older sets with smaller supply
Today, its around $40
Shoot, by the time you are done with your colors, you can destroy every permanent type (Acidic Slime or the Chupacabra), discard or draw, steal or bounce, counter or fetch lands, and recur any creature from your graveyard or into play
5 years ago I don't know what your budget is, but this seems like an ideal deck to be running some sort of fetchlands, even the common variants
Landfall Whenever a land you control enters, put a +1/+1 counter on target Elemental you control