if i wrote a script, and just sat back and collected cash every time it was bought, without having to maintain the domain / servers and pay for bandwidth, etc... i wouldn't be too angry if it was 'only' 50/50.
now its a different story if there is any overhead costs comming out of the sale of the scripts.
Sell PHP code? HA! There are plenty of free alternatives out there to pay-to-use code. I'm not bashing your idea before you get started, but, this will help you leanr the easy way. Sellign PHP code is like trying to sell anything; If it's not unique, it won't sell. It's a simple fact of marketing. If someone needs somethign quickly, or they are on a tight budget, i think they're gonna simply choose a free project rather than a pay-to-use one just due to the fact of budgeting. The less money you spend (if any), they beter off the pay is for you...
EW: Not always true. There are many reasons to choose a Pay-For project then a Free project.
First, being free doesn't mean it's open source. I still remember when the MySQL Front developer said he would stop developing it. It was free, however, so many people had come to rely on it, and now it would never be improved and bugs would never be fixed.
Sure, you don't have the same guarantee with commercial software, but at the same time, with commercial software the developer usually has both monetary and legal incentive to develop.
Another reason a paid for alternative is that usually the support is better. With a free project, it's never assured. No, the person doesn't have access to forums, chat rooms, and mailing lists. Forums and chat rooms about don't cater to downloaded scripts. Unless the developer of the software offers up forums or a chatroom, their is no guarantee. Also, the help recieved isn't always the best.
When your running a business, that sort of sporadic assistance isn't always good.
Think about it. The software breaks, and you log into a chat room with the boss breathing down your neck to get it fixed. You have to deal with chat room immaturity and wade through extra fluff to maybe get your answer.
With paid for software, you expect to get professional, timely support.
Lots of people still value support and the extra services that go along with it with the sale of a product.
Some of the major online programs like phpBB, phpMyAdmin and PHP-NUKE would be the only things that would have notable support to those of commercial companies.
Support, service and reliablity will always be a factor in marketing then just the cost.
my thaughts were more to those who needed something quick and easy, garunteed to work. i have been trying my hand at building a dynamic photo gallery for quite some time.. if i could buy one for $15 that does exactly what im looking for i would spend the kash and learn from the code rather then the ol trial and error method which isn't working out so well for me either nothing works, or i get something working that breaks something else.....
things like scripts to start a secure session and interact with paypal would sell well if they were 'plug and play' type scripts that just add onto the site without being too messy. at least i think they would. sure there are a lot of people who could do it themselves, but they probably cost more to a small buisness then something simple like this.
i know people who sell site designs the same way. there are lots of people who could design a good site, but for $100 you could have this nifty looking site with lots of bells and whistles.