We do full Reverb services at £69.99 which is all seals and all oil (the oil to operate the remote is separte to the oil in the post itself)
Seals for just the post (air seals, bushes and pins) are also available for home ‘basic’ services.
I Think you need to look at them like forks and shocks, in that they need to be serviced Fully every 12 to 18 months, with them being cleaned and re lubed every 6 minimum reallt to keep them tip top. Quite alot of force is put on them and they’re going to get covered in dirt too.