I assume you are talking about a product like this:
Everbilt 3/16 in. x 125 ft. Stainless Steel Wire Rope-13950 at The Home Depot
Standing rigging is normally 1x19 stainless cable. The stuff at Home Depot is much more flexible and intended for low-tension uses like building deck railings.
Additionally the proper wire isn't that much more expensive. The 5/32" 1x19 cable used on your boat should be about 50 cents per foot. The expensive part is in the ends and the tooling to put it all together. Buying everything in one place and installing it yourself can probably save you money by having someone else do the swaging of the ends onto the cable.