That new computer ending up being more expensive than you originally planned, eh?
Well, I recently had a re-think of my gaming collection as well. I didn't have any pressing need for money though. Maybe reading my reasons for the ones I sold will help you?
Basically I evaluated each console based on various factors, this is how it played out...
SNES: Lots of good games, but the cartridges are skyrocketing in price, making it quite costly to actually collect for. Emulation of it has been perfected. Could always keep the controllers and use a SNES-to-USB Adapter.
I ended up selling the SNES, too costly to collect for, now. =/
NES: Most games are shovelware, very few interest me, cheap to collect for. Hardware can be fickle and unreliable. Emulation is perfected.
Sold the NES, never looked back.
Gameboy Color: Not many good games, cheap to collect for, very reliable. Screen is bullshit. Emulation is perfect.
Yep, sold em.
N64: VERY few interesting games, cheapish to collect for. Built like a tank, very reliable. Emulation is near perfect.
Sold the N64 without a hint of regret.
Sega Genesis: Few games that really interest me, cartidges are still cheap, easy to collect for. Emulation is perfected. USB Adapters for controllers exist. Was the Console of my childhood.
I sold the Genesis...There just wasn't enough games that I liked for it to justify keeping it. I did keep the controllers though (couldn't give up those D-pads!). If I found one at a yard sale for cheap, I'd get another one.
Atari 2600: Neat to experience for the first time, console itself looks awesomely 70's. Literally 0 games that interest me. Cheap to collect for (Why would you, though?). Emulation is perfected, if I ever wanted to play it again (Highly unlikely). Controller adapters exist. Why do I have this thing?
Definitely sold the Atari
Commodore 64: A couple interesting games, cheap to collect for. Love the history around it, and its potential. Emulation is perfected. otherwise it's pretty useless
Sold the Commodore, though I felt a slight tang of regret (Not much), I'd buy another at a yard sale.
Dreamcast: barely any good games, but not expensive to collect for. Really neat hardware. Basically only useful for Shenmue 1-2 and Skies of Arcadia. CD reader laser is known to burn out often, needing replacement. Emulation is near perfect. Controller adapters exist.
Sold the Dreamcast, I couldn't convince myself to keep it for just 3 games, even if the hardware is neat. Haven't regretted it.
Original Xbox: Barely any exclusives I like, and the ones I do like were recently released on PC. Cheap to collect for. Has the best graphics of the multi-platform games. Decently reliable. Very easy to 'hack' to install homebrew software. Emulation is possible on PC, but not practical.
Sold the Xbox. No real reason to keep it.
PS2: Loads of good games, not too expensive to collect for, still useful as a DVD player. Emulation is good, but requires a decent computer. Controller set the standard, so no need for adapters.
I'm keeping the PS2 for the foreseeable future. Too many good games to give up
GameCube: Not many exclusives that interest me, cheap to collect for. Built like a tank, very reliable. Best Controller ever designed. Emulation is pretty good, but not perfect, and requires a decent PC. Controller adapters available.
I sold the Gamecube, but ended up regretting it later on. I'll pick up another one in the future.
486 Computer for DOS Games: Used to be a necessity before DosBox became stable. Now?...Not so much.
In the process of selling it.
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I think that about covers it.
Personally, I'd say sell off the ones you're not absolutely in love with now. Because you'll always be able to buy replacements later. Especially if by selling these, it will fund a way for you to make an income.
I totally know how you feel though about just...Wanting to keep 'em. I'm like that right now with my 486 Computer. I love that bastard to death, but I know I'll just never use it. So I might as well let it go for now...
However, as others have said, don't you dare sell this stuff for a low price. Get on eBay, and look up what each item goes for individually. Otherwise you'll likely get ripped off.