I'm working on a small simple program

that I think I can sell to people.
Problem is piracy, and here's my current thoughts on how to fight it:
A: Make limited lifespan versions available for free to everyone.
B: Charge a few $'s for unlimited new major versions, no upgrade policy.
C: Give the programs a serialnumber and built in help on how to buy a
legal copy.
'A' will help in marketing the thing.
'B' means the resistance to buy and also to upgrade is low, and will also
ensure exponential growth in income if the program is a success. Will
greatly compensate a low price.
'C' will help people using copies of full versions do the right thing.
(antipiracy code inside the program is meant to be obfuscated and nearly uncrackable)
What do you think about this plan

Its a nice plan BUT (big but), most if not all antipiracy just hurts the people who actually pay for your product. Pirate cracking crews crack the product and ship it before or on the day of release without the protection or annoying nag screen/net requirement, so the only people you will be annoying will be the people that pay you for it.
To get around the piracy issue make a product that everyone wants, hell you will still get some piracy but look at it as free advertising and not a bad thing. Hell if people pay for your software thats a good thing, if hundreds pay but a handful pirate even better.