In my honest opinion, a total waste of money.
Here is a free tip for successfully germinating seeds, works 100% of the time (true that not every seed i've ever processed had germinated, but it wasn't due to the method, else no other seeds would not have germinated). Actual % of seeds that cracked is in the 90 percentile range.
Obtain either distilled water or Reverse Osmosis; place small amount in a drinking glass; mix with 3% hydrogen peroxide at a ratio of 1mL/L; place seed(s) in solution and allow to soak for 24 hours; take a piece of paper towel (no perfumes/no ink deco) and soak up the water that the seeds were in; fold paper towel twice, place seeds near the top, with the pointed end of the seed(s) facing towards the long run of the paper towel; fold paper towel and place in an airtight baggy; place the baggy in an upright position near a warm area, but not too warm (20-22c); leave seeds undisturbed for two days, at which time open the baggy, unfold the paper towel, and prepare to plant; any seed that hasn't cracked most likely won't, but plant it anyway just in case.
How much additional expense? In a typical household, nothing, most have these materials. If not, then go price shopping for the following items:
Distilled Water
3% Hydrogen Peroxide
Paper Towels
Airtight baggies
Plant a seed, free da weed!
Happy farming...
...
edit: i was stoned and a jerk...my apologies