Here in DP,
When you're selling anything most likely people will start asking for a review copy. So, you basically can 1) Offer a free review copy to a reputable active member, 2) Offer a discounted review copy also to reputable member, 3) You can choose not to offer a review copy (although the latter will most probably kill your sales thread.). Looking at your history here, most likely people will insist on free review copies.
If you can provide good support for your program, then by all means sell many copies here. Like you said, you can also make it as a paid service or sell it through network like CJ, Clickbank etc but I honestly advice selling here first before switching to networks like that, build your customer base.
Although, like other program, we as a customer want to have the best support from the script author as we can get so make sure you WILL support your program.
Who knows, if your program is really makes wonder like what you claimed, you soon will have a dedicated product with affiliates and can earn more than you imagined.
Other than that, I wish you good luck!