Well to follow up. As you have the only iso engine being offered. You are allowed to set the starting price. Though Randomfellow has a point.
Yes "anybody" can make an iso engine. But then compare time spent on the engine. vtrix is right on figuring price. The more niche the closer to your expected pay wage you should charge.
As an example
C2 is a windows tool. Thus makes sense that on a cost ration it's cheaper than your iso engine.
Your iso engine can only work inside C2 and no other game tool.
Then your iso engine is only for people who want iso games.
So it makes sense that your Iso engine on a scale cost ratio costs more per hour of effort than C2. Same with a tool like Spriter that is meant to target EVERYONE who makes 2D games.
I find Unity asset store ranges from $5 to $100. With unique on the higher side.
so someone could either spend 16 hours at $40/hr($640) or they can spend 30m to purchase and integrate for $50. Ok. I don't get paid $40/hr. but that is apparently the going rate for experienced programmers in my city. And I don't know about other, but I have seen a dramatic increase in the number of people who CAN'T make new things.
Also if I may offer a few more pieces of advice.
* CLEAN. Remove all disabled code or leave a comment why it's in.
* DOCUMENT. To make code usefull make sure people have comments to read as to what it does and how it goes about it.
* POLISH. try to reduce fluff code
* SEPERATE. if you have sample code. Make sure it's not integrated into the main engine code.
* MINIMIZE. when I integrate(ie copy/paste) make sure it's as little as possible.
and demo it. Good graphics are only for people who don't understand the code they are buying. People who understand the code they are buying don't need good graphics.
oh I also forgot to mention. No matter what you need to run on the honour system. There will always be people who will infringe or distribution. However you can at least get a License agreement in your code and upon agreement of purchase.
That way if the code is distributed you have threatening recourse. Although there is no way to enforce such. but it's at least it is in there.