In my experience (and it's over decades but I'm no cork-sniffer tone-snob), it will depend on where & how you use your effects.
If you do exclusively studio work with Uber Quiet environments your components will make a huge difference in the quality and voice of your stuff.
If you gig in bars with neon beer lights buzzing away 3 feet behind your amp, house wiring that hasn't been upgraded since your Dad was born and a room full of drunks yelling as loud as the band, any resistor will sound exactly as good as the next one at the same measured value.
YMMV. Most people will be somewhere between these two extremes with most of my experience being a little more (OK, a lot more) toward the second scenario.
What I like about electronics graveyards is the variety of sweet goodies like weird knobs, switches and enclosures. Stuff you could never find anywhere else in 12 years of searching. Sometimes I bid on electronic junk on ebay just for the knobs and switches. It's double bonus if it looks like crap and nobody else bids on it so I get it cheap! I scored this just about 2 weeks ago for $19:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0273934608I got a bunch of SWEET vintage USA made tubes and a TON of awesome knobs that will go on every effect I gig with. I already get someone at almost every gig doing the "WTF" look at my pedal board. With some of these controls on them, it's only going to get farther out there.
BTW, these goofy things were crammed FULL of 1960 vintage Allen Bradley pots of every value you could think of with not a single solder snot on the cases of them anywhere. I wonder what those would be worth to some of the vintage LP guys who pay $300+ for a single bumble bee cap of the correct date? I'm guessing more than $19.
Cheers,
- JJ