Hi Gabriel.. This has been a hot discussion topic in many forums I've been into.. Kohler Purists will only buy the expensive Kohler parts. Others have purchased the rebuild kits available on EB HERE and had good results. I've used both types and all it really comes down to is your personal taste and size of your wallet. I see the prices are low due to the time of year.. Wait a few months and things will cost you more!
There are a few Site Sponsors you can give a call to see if they can give you a deal as well.