This system already exists, and already functions better than it would if the USPTO were involved. If you want a patent to go into the public domain, do the following:
Not only does this procedure not need the involvement of the USPTO, but it has the added benefit of you not needing to pay any more for the patent than the selling price the owner is willing to accept.
On the other hand, determining the "selling price" is not quite as simple as "150% of the development costs". The value of a patent is not that it is a way of recouping your development and patent prosecution costs; there are plenty of accidental discoveries that turned out to bring in a lot of revenue from very little development costs. The value of a patent is that it gives you an exclusive right to an invention. So the true value of a patent is the revenue it will allow you to bring in over its lifetime, from sale or licensing, or from litigation awards. Most companies also treat patent acquisition as an arms race: as long as you and your closest competitor both have big patent portfolios and are each infringing on the other's patents, and as long as patent litigation is as costly as it currently is, then you can have occasional skirmishes with out-of-court settlements being traded back and forth while avoiding an all-out infringement litigation war.
So, in neither case is a patent owner going to be enthusiastic about selling if a nonprofit shows up and says "we'd like to destroy your patent at the price of its development costs". To buy the patent, you'd have to cover the cost of anticipated revenue from that patent and the cost for having lost a deterrent against litigation.
Okay, let me explain for you non-biochemist computer guys what this means. Take a computer, break it down into the smallest possible parts you can. I'm not talking about the hard drive/motherboard/case level. I'm talking about the level of transistors, resistors, ICs, connectors, motors, and the little blue LED that blinks whenever your hard drive spins. Now catalog everything. Keep a record of what you found where, and how many you found (eg, you found a laser in the DVD drive but not in the motherboard). So now you have a parts list, and a good idea of what parts to expect where. If you start finding unexpected things in unexpected places (like a SCSI connector on your video card, or an audio out port on one of your DIMMs), that tells you something is wrong.
Take a look at the database entry for something common like glucose. It's got
Now what's missing is a lot of information about the connections, so technically this isn't really a map (because it's missing relational data), but a catalog. We need to know how each chemical turns into another, and what does the conversion. It's kinda like having a complete parts list for the computer, but not knowing how most of the parts fit together, nor how many volts and amps to run through the wires. Some of these connections we already know. I have a very large poster on my wall illustrating the more common chemical pathways in various organisms. It's not nearly as complete as this catalog in terms of chemicals, but it's got a lot of connections.
The connections are what's really useful. To continue the computer analogy, if you know that the blue LED connects to the hard drive, then if you don't see the blue light blink, then there's probably something wrong with the hard drive. A significant number of drugs aren't active in the form that you take them. They become active when the body (usually in the liver) converts them from the delivery form to the active form. But some people, because of their genetic makeup, convert the drugs differently. They turn them into different metabolites. These metabolites might be totally inactive, or even toxic in some cases. So if you know the connecting system, you can put a drug in, look for what metabolites result, and determine whether or not that person should continue taking the drug.
Without life, Biology itself would be impossible.