i have found i my search that all in price is comparable where ever you go.

keep in mind in addition to springs you will also likely need rear shackles and u bolts, maybe rear hangers, and if you really want to go nuts new front hangers as well.

unless your old spring pack is in reasonably good shape, probably not worth messing with. i was going to building my 66 darts springs and when i took them apart the leafs were literally pitted (between springs) to the point where they looked like they could easily fail.