If you own a machine shop or can get the machine work done at a reasonable cost, you can save some money using the stock crank and rods.
On our current 505 build we had a 77 440 with cast crank that needed to be turned, and was external balanced, so for us a stroker kit was an easy choice. Costs to consider with stock parts is turning/polishing crank and balancing the rotating assembly. For the stock rods, upgrade to ARP bolts and usually big end needs resizing. Add the cost of the piston press pin R&R. Block machine work should be the same, except need to clearance oil pickup boss slightly with the stroker kit. I consider the cost of the pistons to be about a wash for equal quality parts.
What you gain with the stroker kit is more CID, higher quality materials, stronger 7/16" rod screws, much lighter pistons, plus lighter full floating piston pins. Also, the stroker kit pistons use thinner piston rings, where most of the stock style replacement pistons use the stock thickness ring pack.