Repair or Replace?

OK, So, I have an Original-Generation, "Day-One" Purchased, Old 3DS (non-XL) Console that has developed a number of faults, both Minor and Major. For some "Off-The-Top-of-My-Head" Examples: The Charging Port is Rusted; The 3D Slider is Broken; The Cartridge Slot occasionally has trouble recognizing Game Carts; The Wi-Fi Switcher gets Stuck; The Volume Slider is Busted; The SD Card Slot sometimes Fails to Read the SD Card; & The Start Button Sticks (but otherwise works and functions properly). What I want to know is, at this point, is it worth it at all in finding somewhere to get it repaired, or would it be cheaper to just Replace (or Upgrade) the System (Preferably to one of the "New" Models)?

 

That may very well be the case. Any ideas on how to clean the inside? While I try to keep the outside well-maintained, I'm not really all that confident in my own abilities that I won't screw something up upon taking it apart or putting it back together again...

Yeah, that's kind of what I thought, too. Do you have any suggestions on where I can find a good "New"-er model at an affordable price? I've seen that GameStop sells some "Refurbished" New 2DS XL systems at a decent price, though I'm kind of on the fence about getting one. I don't necessarily MIND the lack of 3D (due to having to live without it for most of my 3DS's lifespan thanks to the aforementioned broken 3D Slider), but I know their Refurbished consoles can be a little "Hit-or-miss." They DID have some "Mint-in-Box" systems online just the other day, but I kind of missed my chance to get one, and now I'm unsure if they'll have any more...