Most of the time, they aren't broken outside of Affinity. But being broken inside Affinity alone is what justifies their banning.
Artifact lands are the difference between dropping your hand on turn 2 (or even 1) and dropping it on turn 4. They add to your affinity count and your metalcraft count (for Mox Opal), they add to your Cranial Plating boosts, they make Master of Etherium bigger just by being there, and they can be sacrificed to Ravager for those last points of damage (and/or life loss, if you have Disciple out as well).
The cheapest playset of Force of Will I saw on eBay was almost 300 dollars, and the cheapest playset of Wasteland was 200-220.
But yes, buying entire decks can end up being cheaper than buying the cards separately. Also, it is worth mentioning that buying a Caw-Blade deck on eBay costs around 500-550 dollars, which is still cheaper than Fish.
A playset of Force of Will is around 320 dollars, and a playset of Wasteland is over 240 dollars. The barest shell of your deck costs over 560 dollars, and you still need 67 more cards, quite a few of which are in the double digits. (Mutavault, Umezawa's Jitte, Æther Vial, et cetera.)
And even after all that, you have a single deck. What if you want to go into Zoo? Now all you have are Wastelands. High Tide? You need 120 for Time Spirals and 1000 for Candelabras.
PnBoots has been banned for being a gimmick of troll jkfranklin.
http://cgi.ebay.com/MAGIC-MTG-Original-FOUR-FORCE-x4-alliances-/220783838231?pt=LH_DefaultDomain_0&hash=item3367be0417#ht_500wt_1156
http://cgi.ebay.com/MTG-Force-4X-/150605768829?pt=LH_DefaultDomain_0&hash=item2310cda87d#ht_500wt_1156
all within the last day.
and your 600+ buy in going for a mere 400 dollars http://cgi.ebay.com/Force-Wasteland-X4-Magic-Gathering-Signed-/290565504751?pt=LH_DefaultDomain_0&hash=item43a70dbeef#ht_603wt_1139
remember if you're boarding in leyline of sanctity specifically to counter jace you were already losing anyway.
first, playsets of FoW run about $200-245, and wasteland anywhere from 175-200. For example you could have bought in this whole deck for 610. http://cgi.ebay.com/MTG-Legacy-Fish-Force-Wasteland-/260786023655?pt=LH_DefaultDomain_0&hash=item3cb80eece7#ht_602wt_1139