(i'll apologize up front for the lengthy ramble that leads into my own philosophy on base cards and set building)
well , as i proudly state on my own card site : I suffer from what mothers used to call "pack-rat syndrome" . I like to keep EVERYTHING . In my collecting , I like to own one of every card .
i actually still have about 2 million cards here right now....in the past i set up at shows and flea markets every weekend , often coming home with far more than i began the day with....then about 14 years ago when i had "only" about half as many cards as i currently do i started on a project to get better organized... i decided before continuing any further activity with cards , i'd first break everything down by sport and then once that was done i'd further organize each sport by year/product....i made it through my extremely small amount of hockey and about half of my basketball before that project got put on hold due to a job change....i'd spent nearly 6 months on the project and made it through less than 20% of my collection....
now , i sit here with so much material and so little free time to get it all organized....i have hundreds and hundreds of boxes filled with random odds and ends....last year i resumed my project and made a little headway but never came close to finishing....a few weeks back i finally got started (yet again) on my organization project....this time , instead of labeling each box with its actual contents , i'm labeling boxes with generic tags (ts-1 = triple shoe number 1 , 3200-1 = 3200-count box number 1 , etc) taped to the outside....each box contains cards divided by set with index cards as dividers ....then i use an excel document to keep track of the exact contents of every box....if i have a box filled with 3 or 4 products and find another stash that won't fit in the box , i no longer have to change the label - just move them to a new location and update the spreadsheet....
each night that i get a little time to go through another box or two and move some items to their "proper" homes i feel a sense of satisfaction....granted i'm months (and months) away from finishing this project as i've only managed to get 10 3200-count boxes and 17 triple shoes of base material organized this way so far but any progress is good progress....now i find it much easier to go track down specific base (common) cards for trading and once my project is finished i will have virtually everything at my fingertips and easily located within a few mouse-clicks ....
now why did i ramble on like that ? well , besides being a pack rat , i am a HHHUUGGGE set-builder....i've finished hundreds...i have literally thousands "in progress"....for a collector like me , if i have ONE CARD from a set , it's in progress until the last one arrives...obviously many will NEVER be completed , but that won't stop me from TRYING....over the past month i've become an active trader here...most of my deals have involved sending out large numbers of base material....granted i may not have all the hot new popular sets and stud prospects or HOF cut autos , but i am more than willing to dig through my collection to look for even a handful of base cards for others who need them to fill sets.....
i love autos and GU and rare items as much as the next guy (maybe more)...i love vintage...i love anything numbered ...i love parallels....i mean really ...i love cards in general....it really pains me to see the attitudes of so many collectors these days who feel base and even inserts are garbage...those aren't true collectors...too many people whose eyes are merely filled with dollar signs at thoughts of the next big chrome sale....i could regale you with tales of buying the "junk" left from box breaks at my local flea market or even the local shop....many a time a dealer's son/helper would bring me 10-12 boxes from which they pulled only the autos , gu , or numbered items and they'd sell them to me for $2-5 per box......(that's how i got a couple 91 stadium club brett favre's plus a few 2000 bowman chrome tom brady rookies

) i cringe each time i hear a "collector" on a card message board brag/whine about trashing or shredding thousands of cards they either don't like , want , or have room for.....i can assure you , there are MANY of us out there would would be more than happy to have the burden of more cards to sort....
ANYway....i better wrap this up before it exceeds the character limit for a message....in summary , i'd just like to let it be known that set collectors ARE still out there....and true set builders can be just as happy with a nice 1982 topps #459 (bruce berenyi) as with a babe ruth cut sig 1/1 ....
(berenyi was the final card from my first complete topps set back in my junior high days - and fwiw , i was so into set-building , even as a teen , that at one time i knew every card in the 1982 , 1985 , and 1987 topps sets by number - guess that just proves i had more time on my hands than common sense back in the day)