First, let me say I do not own an intellivision, I can't test these games, but they're well kept and clean.
I can accept paypal (cc's okay, no added fees from me), and money orders or cashier's checks from the US only. I might trade if you've got games for an atari 7800, 2600 or the original nintendo. I'm fairly negotiable. Check out the price guide link skunkworx shared in the first reply, that's what I'm going by, minus a little as I hate selling things I can't test.
These games are all in their original packages, opened, damaged and squashed packages. These are NOT for the picky collector of mint stuff, they're all damaged boxes and manuals, some more than others. If you'd like photos, just ask, I'll take pictures. Questions? Please understand I don't know jack about intellivision, but I'll try to answer it.
Unless otherwise noted, all games include 2 controller overlays and instructions, and I'd be giddy with $3 a piece for em.
Star Strike
Skiing
Skiing/ Le Ski (english and french packaged)
Horse Racing
Major League Baseball (no instructions, 4 overlays)
Space Armada
Sea Battle/Combat Naval (english and french packaged)
Space Hawk
Snafu (no instructions)
Thunder Castle (no overlays- a rarer game- $9 sound fair?)
NHL Hockey
New Beauty & The Beast (one overlay)
Bowling
Big League Baseball (cart and box only- no instructions or overlays- a bit rarer, maybe $6 sounds good?)
Frog Bog
Intellivoice- voice synthesis module, english language bilingual (with french) box- looks darn nifty, the box says it plugs into the game system and if you put an Intellivoice game cartridge into this doodad it will add in both male and female voices generated by game play including cheers, strategy and comments. Does nothing extra with non-intellivoice games, surprise, but it'll let you play them without unhooking it from your system. Includes box, 1 set of instructions with english and french text, one set of english only instructions, and a brochure showing some games. it's kinda hefty so I'm guessing at least $5 to ship it, so figure that into things if you're interested.
BOXES ONLY- FREE! pay the shipping and it's yours, I can't bring myself to toss em...-Astrosmash w/instructions and one overlay (it's a one player game)
and space battle box with 1 overlay