After a few hundred hours of operation, what it cost you will become irrelevant and you'll only remember the useability.
Yup, this is exactly what happened to me, I don't remember what it cost.
I installed a 3rd function valve for my grapple, and 4 rear remotes. 2 have float, and the other 2 are standard 2 position. I used stack valves so I can add more as needed. Where I made my mistake is I didn't add a motor spool valve or power beyond, so when I use my log splitter I have to use a bungee cord to hold the valve open, which I really don't like because it's basically mickey moused. I think there is a link in my sig to a detailed report of exactly how I did the work, as well as breakdown of costs etc. with quite a few pics.
EDIT: I just checked my thread, and it cost me $870 for the entire rear remote setup including QD's. The 3rd function was right around $800 from WR Long which included brackets and everything I needed to install it.
Note that I did get a few fittings for no cost to me, so figure maybe an additional $40-$50 for those fittings. Also, my mounting brackets for the rear remotes were no cost, so realistically I'd say for around 1k if I had to buy everything the way I did it. (rear remote setup)
At the time I was doing this, MtnViewRanch didn't offer the valve kits he offers now. If I were to do it over again, I would go with some sort of rear remote/diverter setup combination from him for all my rear remotes, so the valve's wouldn't take up as much space, but I'd still have numerous remotes out back. I don't think the additional cost of the 3rd function is really "worth" it if your looking to do this economically. The diverter setup would be just fine, and in some cases better (with minor disadvantages depending on your personal preference).
Of course, this is with me doing all my own labor and quite a bit of time in learning hydraulics (I knew absolutely nothing when I started). If you don't want to do any of the work, then it may be better for you to just pay the dealer and be done with it. However, this will almost certainly be the most expensive way to go, while more than likely not getting as "nice" of a setup as you could with a true customized job. (in regards to functionality/versatility)
......now that I've used the hydraulics, what do I value them as????? Priceless.