I feel like if you want to make spawners worth more, you should be able to mine them and instead of a spawner, you get a spawner shard. Right clicking a spawner shard makes a GUI shop opens where you can trade spawners shards -> for spawners.
(I've seen this on other servers and it works really well, making the spawners actually worth more than the sad 2k it is worth.)
Ik everyone will hate on this idea, because you would actually have to invest in spawners. Of course, if you misplaced them in towny you should be able to get the spawner back instead of a shard. (also because people have grinders there already)
#trying to hijack this thread.