Here's an idea to get players more involved with investigating new spells: reveal the actual spell info to the player as they successfully learn more and more.
It's not as exciting as a player coming up with their own spells, but not everyone wants to get as creatively invested. It could also be good if you want more control over the spells that will be possible in your campaign, or even if only a single caster can know any one spell at a time (wasn't that Mr. Rient's idea?).
(Why make players go through the process of research if you already have a list of spells? Well it can still be engaging as a mini-game, especially if you have some kooky random failures possible during research.)
Anyway, let the player see a list of possible spells they can choose to research. They'll have to make a decision based on just the name. Maybe you'll allow them to research incrementally into different spells, finding out a little more about each one before sinking all their time and money into learning one. Maybe you'll allow them to try casting a spell before it's fully researched, but if you, the DM, carefully craft the spell ahead of time you can make this very risky.
Let's take the Fortunate Punishment as an example. And I should pause to say the last time I wrote about this spell, I made it seem like I invented the spell in the comments (hell, I didn't remember if I had, or one of my players, or . . .). But it was actually invented by the brilliant Stuart. So thanks to him, and sorry about that, sir. Now the example:
Now, this would take a lot of work on the DM's part to make each reveal dramatic or a tease. But then, you could probably even take the standard spells and hide range, material components, and casting time, to be dramatic too, depending on the spell.