Non-budget versions of Lantern run about $800-1000 depending on how you build it. That's mainly due to things like
Mox Opal, and sideboard cards like
Grafdigger's Cage and the different Leylines.
Strategy-wise, the goal is to create a lock on your opponent by getting to 0 cards in hand and playing
ensnaring bridge, then using mill rocks like
Ghoulcaller's Bell and
Codex Shredder combined with
Lantern of Insight to manipulate the top of your and your opponent's decks to make sure they draw no relevant spells. In my build, I use
Pyrite Spellbomb and Aether Grid as alternate win conditions. Most people generally scoop once the lock is in place, but in case they don't, you can recur
Pyrite Spellbomb using
Academy Ruins.