I haven't found an underpriced bargain 45 in several years, but that is mainly because I haven't done the footwork to get out there and hunt - the books take nearly all of my time. Even then, the places to go are limited, and the competition is fierce. There are the guys who don't collect garage, but they know prices and what to look for, so they can re-sell. Record shows are polluted now with record pimps. Just go to Allentown!
My last bargain score was a VG minus Beep Beep & The Roadrunners for $20 which i put up on ebay, back when it wasn't as easy to rip off sellers. I got over $800 for it which was ridiculous.
These days, I consider a good buy or bargain when i can save a bit - for instance, a 45 that typically sells for $500 and i can get it for $400. I really feel for the younger / newer collectors - it's an uphill battle for you folks. The internet has leveled the playing field, making it the go-to place for finding stuff, but you have to battle against everyone else with a computer hookup and net connection. The old days, you had auction and set sale mail order lists, and places to go in person - stores, record conventions, meetups....I really miss the days when a bunch of us would get together at the Waterbury, Connecticut record shows. We'd end up getting kicked out of the show for trading & selling with each other (the old timers who ran the show like Adolph Hitler insisted that you had to buy a table in order to buy and trade). We'd then walk out tot he parking lot and hang out there til we'd get kicked out (can't sell in the parking lot, they claimed) so we'd drive up the road to Blackies, the old fashioned hot dog stand built in 1911, and wheel 'n' deal there.
Those days, a guy like NWBuckeye would show up with a couple of boxes of good 45s. Or BN would show up with a box of goodies. Still remember the day when BN brought his buys from the Mark Martucci collection: Larry & blue Notes "In & Out" VG+ $50, Bad Roads "Blue Girl" $100, Jackson Investment Company VG++ $150. Spending $300 was a lot of money at one time for records in those days (1988-90). By the mid '90s prices were steadily climbing. Before Mark Taylor came along in 1996/97 and started the free-for all (people pullling 45s from their collection and selling to Mark), there was a guy from Florida named JD, who paid what we all thought were crazy prices. He was the first to pay $500+ for a Mourning Reign on Link with the pic sleeve. There was a large quantity of that with the sleeve, and it usually sold for $250 at most. When JD came into the picture, prices got crazy. He also paid $500 or 600 for the Split Ends "Rich With Nothin" long before any quantity was found.
When the Kesteloo collection was purchased by JJ, more guys with huge wallets got into the frenzy. i lost out on the Sands on Capri, one of the Kesteloo collection 45s auctioned by JJ. It either went to JB in Texas or GW in CA. The bid was $1200. By this time, it was apparent that the really rare stuff would always be above my means. I'm glad I was able to obtain the 45s I now have before the days of the internet. I still grab a lot of great stuff on ebay, but these days, it's 45s that I can get for a lot less than what dealers would usually ask.