Thats not a bad price (27 shipped) for the pak and charger. The only thing I dont like is the connector and if you have a rapid charger you will have to more than likely create a custom connection. Also, it hangs out, which would drive me nutz! Lastly, I do not know who makes the cells in the pak. I like my Sanyo's.
I installed the charge jack, switch and pak. My price was definately more than 27$ total, but, I got the setup I wanted. Nothing exposed! Cutting out the charging jack is interesting. You can use a dremel and drill or you can use an exacto blad and keep tracing the same rectangle until it cuts through. Even though I have a dremel, I opted for the razor blade to make it cleaner. So I thought anyhow.
The yellow is just fuel tubing covering my linkage. Just for looks.