Hiya BL,
It is sad that they are so expensive because as Ramona said, they do the job so well.
If you do you will only need the smallest self tailing winch out of the range for a 25'er, so something like the 20ST from Harken. Dead simple to service to boot. My head says don't do it because of the over capitalization, my heart says do it as there is no negatives aside from the cost

.
I upgraded to ST's for sheet winches on a 26'er and loved them to bits, especially when short handed. You forget about the price pretty quickly, the enjoyment lasts a long time.
Cheers!
SB