One has to optimize for the 'harder' thing being done. So if the challenge is getting the MVP written, then this order makes sense, the risk on the $3000 is less than the risk on the $5000. If the challenge is getting people to understand it, then doing the landing page first makes sense. From hmexx's point of view $8,000 is at risk either way, except he "knows" he can do the customer acquisition part but doesn't know if someone can do the "MVP" part.
One of the realities this discussion has highlighted is how little young engineers (and some older ones too!) value the whole marketing/customer acquisition thing. But the beauty of it is that when the risk arbitrage is low enough, that doesn't matter. One has to ask is there a 'funding round' that is earlier than a 'seed/angel' round? Maybe an 'idea' round. Two people come together, one proves they can execute on building an MVP and one proves they can execute by acquiring customers, then the pair take the next step (assuming the thing works and customers are found). This really side steps the whole "I've got a great idea if I could just get it off the ground" discussion into "What are you willing to bet?"
That nails it perfectly. I like the OPs proposition. I like it so much that I'm now wondering what would be a better counter offer, and I've failed to come up with anything so far. This little trick could kickstart a whole new phase in the start-up world.
Unless the OP turns out to be Jason Calacanis ;)
First mover advantage, sometimes you show the Johnny-come-latelys all the mistakes they can avoid, and how they can improve upon your product by examining your weaknesses and flaws because you rushed it to market.
If you are a first mover, consider having in your business plan what you do when the 'heavy hitters' decide to copy your product and do it better. They most likely will so plan on it. Do a total quality management on your product and improve on it every chance you get before the copycats do it better.
As someone said here earlier, idea is just a multiplier of execution.
The Amiga was basically a launch platform that went away for many niche market software. If the companies that developed those for the Amiga had developed them for the Macintosh, they'd still dominate today.
So do I. Remember Pagemaker vs. Quark Express?
This way you risk only $3000 (or less) instead of $8000, and the developer will be much more motivated to build it knowing it's already an idea with a real potential market.