[warning: slight ramble]
Modules for software such as modx would be good, while there is some good existing stuff out there, too much of the advanced functionality requires alot of work, blueprints and similar solutions would be good.
Server side php, and .net can’t be stolen so easily, which would be a more effective product. Yes people can purchase it and then re-distribute it, but is that really a viable argument? as this can and has happened to commercial software such as expression engine ipb etc., they just have to knock it on the head, it’s a fact of life that crooks exist. TF are already aware that templates ARE being re-distributed else where, along with commercial wordpress theme’s, illegal music, pirated films etc. It’s a curse of the media industry as a whole.
Alot of the commercial software contains snippets to contact the author if it’s not been purchased, or if it’s invalid in anyway. These tend to be nulled, by certain pirate groups, so that’s not a viable counter-measure either.
However, the down sides are, client side coding can be easily taken. Who’s going to buy a js snippet without testing it first?
Having said that, every themeforest item with a live preview can be taken within seconds, while this poses a problem, it’s not just applicable to tf and really should be calculated in. If your not willing to have one in ten (exaggerated, i hope!) people steal your stuff, then don’t put it on the internet. TF seems to be thriving despite this issue, other marketplaces should do the same?
Other downsides however in regards to snippets, is that there is alot of active forums out their with people more than willing to write small snippets/plugins for other people. While 90% of the time i’m able to reference a script, or a strong direction for them to go in, it’s not unusual for me and others to write code for them (we like to keep our ‘code banks’ brimming with usefulness).
Regulation would be difficult, proving something was built from scratch, not lifted or modified, and keeping things unique. Almost everything is readily available.
I think it’s a good idea, however from what i gather, envato marketplaces are designed to be ‘fresh and unique’ and most things have already been done.
People on this thread who’ve stated they can code it from scratch, think of those that work mostly with design, who have an intermediate knowledge of html/css. Sometimes the support is more valuable. The amount of times I’ve responded to people trying to install lightbox, or a snippet from dynamic drive. Having paid a small sum for the code may not be as valuable as the certainty of having helpful, quality support to go with it.
Also think of those who are creating websites for an idea, or a business they have, or for information they want to share, and so on. It’s viable they purchase a coded template to kick-start them, purchasing a new gallery or something to enhance their project, and then be able to have support when they go wrong.
[/ramble]
I think the pro’s far outweigh the con’s, but where you can draw the line on submission i wouldn’t even begin to know.