@futurestoryteller Well as valid as your points are, I disagree. The world is built on people making money. If I ask you to do 30-40 hours of work for me, are you going to do it for free just because It's something you're passionate about or something that's considered an art form? I doubt it. I don't know about you but I value my time and I think that if people are going to put their time and effort into something, why shouldn't they be compensated accordingly? Musicians love to play music yet you still have to pay to see them live and pay for access to the recording. The same applies here. It's a modders sole prerogative whether or not they choose to release their work for free to the public or not. I mean if you were doing a request for me, I would be more than happy to compensate you fairly for it.
What you're saying is technically true but anyone charging money on here is NOT making money from GTA, they're making money from the work that they have done. 3D Modelling, rigging, scripting etc are all real skills that exist outside of the game so why should that fact be ignored if the work is then used in a game? People aren't being charged for anything here though, this site/forum isn't an online store. If someone contacts another user here and they make an agreement then that's entirely between the 2 users concerned and no one else, so long as they're not breaking any of the forum rules in the process which in this context, they wouldn't be.
I also think you might have underestimated what's actually involved in that $90 you mentioned, that would be a full creation from start to finish of a 3D Vehicle model, to exact specification plus a conversion to GTA. That's easily 70+ hours of work and if you're familiar with freelance 3D work you'll know that's a bargain compared to the going rate for high quality 3D work (Easily $150+ for this kind of work).
There's also the fact that this post is a request and though yes, although a lot of modders here are passionate about modding the game, they may not be as passionate about building a mod to someone elses exact specifications and in that case a commission/donation is perfectly fine because It's solely the choice of the requesting party whether or not they decide to donate or commission that modder. I've seen many artists, animators, musicians and modders online working in a similar manner so It's not something exclusive to this site or even game modding.
About IP, I agree with you but the simple fact is that this community literally would not exist without that dilemma. Most of the character and vehicle models that are ported to this game are ripped from other games like Forza and yet this site hasn't been shut down. Perhaps companies enjoy the publicity of seeing artistic renditions of their products used? Afterall that is what they are, in most cases modders don't have access to exact blueprints for cars or the exact source models used in games etc.
Nearly all of the commissions I take are done through PMs and the people requesting are entirely happy with the terms otherwise they wouldn't be talking to me. It's fair enough that you don't agree with it but neither myself or any other modder taking commissions or donations is breaking any of this forum's rules.
Donation is not the only motivation for modders but you have to understand what you're actually asking for when you make a request of someone here. Believe me modders taking commissions or donations aren't here to try to take advantage of you but at the same time we modders don't want to be taken advantage of either, thus @HRH saying he would be personally insulted by someone offering him $5 for a mod (as would I).
I don't think people on here are emphasizing money as much as you think, It's just the simple fact that if you want a request to be done quickly and effectively then a commission or donation is the best way to go. There's always the option for people to learn to mod themselves as well of course if they're unhappy with the situation, or be content to wait and see if a modder does release their desired mod in time.
I apologise for the long post though especially since @HRH and @Kiryu summed up the situation so eloquently.