No!
1,000 shares * $50/share * (+1/8 tick or 12.5%) = +6,250
1,000 shares * $100/share * (+1/8 tick or 12.5%) = +12,500
You are spending double for the $100 stock so your gain will be double at the same % gain/loss (tick).
Make sense?
Now say you only have $50,000 to spend total...