The plug and play aspect of the HF kit is intriguing, I bought the $100 15 watt version in '05 and used it to maintain one battery. It has been retired to the country to keep a tractor battery from discharging between uses.
I replaced it with a $87 60 watt panel (solarblvd), a $12 controller and $44 of wire! I'm thinking low voltage wire from home depot would suffice for 1/2 the price or less. My usage is less than many folks daily parasite use.
Yep, had to strip the wire ends and even got to use my never opened $12 solder gun from HF to tin the wire ends. Not as easy as plug and play, worth the education and easy.
I still think for the novice, having a remote display, all in one,
like one of these kits, is worth it! Not needing to know where and how to wire shunt/meter(s).