It probably depends on the scripter. If someone pays me to write a script for them, and then they want to release it for free to the public, I'm okay with that (because I don't intend to sell it myself). I'm NOT okay with them SELLING it. I'd be surprised if most scripters intend to sell scripts they've been commissioned to write - maybe I assume if someone pays for it, it's for their exclusive use.
If I'm not misunderstanding you here, that's certainly something I have no intention of doing; they'd be the one making the script. It wouldn't be right to sell someone else's work, unless it was agreed upon. That kind of thing isn't something I'm entirely comfortable with, however.
My plan if I could get this script commissioned at some point was to have it made, included in my current project(s), then released for public use a fair time after the game's release.
I myself, leaves that decision to the one who commissioned the work as long as they don't claim it as their own. I only made that since they asked me to and pay me for it, so I find it just right to let them make that decision.
And releasing it in public has it's drawback on them too anyways, since they paid for it while other people will be able to get it for free...
I haven't seen the video yet, but if I remember correctly about that game, if that was me I guess the base would be around 300... then depending on specifics it can go up, especially if you need it to be compatible with a number of other battle scripts that you would be using since doing that can be kinda really hard depending on the scripts...
Claim it as my own? Not something I plan on doing. If I use something made by someone else in my games, such as a script, their name's going right there in the credits, no matter what. They'll probably get a free copy of the game, too.
In my case, I wouldn't mind having to pay for the script if it meant it could then exist and be used. Unless it's something like a proprietary game engine (separate from RPG Maker), I'd rather people be able to use it. Only in the hypothetical case of the latter would I ask someone to pay to use something like that, so long as it was made by myself or a team of my own and not commissioned out.
As for the script itself, some of the compatibility issues could be handled from the other side, by working with the people who are responsible for the other scripts involved. Other things might require commissioned add-ons, however, if they were intended to specifically add something optional to the battle system. The former may not reduce costs, but it might reduce the amount of work the commissioned scripter would have to do. The latter would likely increase costs a good deal, depending on what the add-ons would do and how complex they would be.
Probably wouldn't be unreasonable to get offers for 500 or 1000+ even depending your actual requirements.
For example, two sprites bumping into each other to take away HP would likely be on the lower end, but full custom graphics with combos and everything would push it way up.
Yeah. This would depend on who would be doing the scripting, and how much work they'd have to do.
I'll see about getting some details of the script(s) up later so that I can get a better estimate.