You can run a China crank, K1 rods, and pretty standard pistons with a 3.8 Stage 1 or 2. With a 4.1, pistons will be more. With an on center, I have $100 in spacers for the cam and crank. Now the oiling system adds some $ with an on center. Just because you have a stage block, it doesn't mean you have to use top $ parts. The China forged cranks and K1 rods will support more power than most will make. It is just nice to have the extra head studs and the stronger block. If you buy an off center stage block for $2000 to $2500, and use the China forged parts like most are using in the 109's the cost difference isn't bad. You will have $1000 in having a 109 girdled. If you do caps and girdle (waste of $), you will have around $2000 in the block not counting buying a block.
I bought a complete stage 2 on center circle track engine intake to pan. It was fresh, never run. I kept the new BMS crank, block, heads, Jessel rockers, intake, dry sump set up, pistons (because they are worth nothing). I sold the rods and front cover. I have around $3000 in the block and crank. I decided to run $1300 Crower rods instead of K1's, and spec pistons to handle 1200hp ($1400). I am using a stock front cover with a Duttweiler pump cover with external filter and lines ($500). I had to buy a sheetmetal oil pan with wet sump ($150 used circle track). I did alot of the assembly and custom fitting work myself, so that saved alot of money. Also buying the T&D rockers for GN1 14 bolt heads is expensive. I still have atleast $1500 to $1800 worth of parts left from the Stage 2 NA engine I could sell.
If you get into a Stage block cheap, it is worth it. Going off center is way cheaper. (stock intake can be used, stock oiling system, narrow journal, connecting rods are cheaper.) If planning to make average 109 build capable power, the China parts are fine. Most people think Stage 2 and think 1000hp+.