If the group is less than level 9 or doesn't have a druid in the party, how many level 9+ druids are there? How willing are they to help? The component costs are already 1,000 GP. Can you get it done within 10 days?This particular point sticks with me as I read through the thread. It seems like your biggest issue is a 5th level Druid exclusive spell.
If that is the case (and your players aren't worried about the random nature of reincarnate bringing them back as a race that ruins all their build plans) then why not simply house-rule that Reincarnate needs to have an intact body just like Raise Dead does?
I mean, if every solution is met with "But Reincarnate" then is seems like addressing that is the way forward for you.
There would be a lot of barriers in a lot of campaigns. Unless there's someone in the party that can do it, IMHO if it's easy to bring someone back from the dead it's because the DM has enabled it.