Usually lots of garage sales around depending on time of year and your location in the good old USA. Some states have a lot, some not so much...hard to get to or have a garage sale if you live in the middle of a wheat field, desert or a swamp.
I'm sure we all have our favorite techniques for buying at these sales. Bundling is probably a common favorite.
Today I used a modified bundle approach. I put together two or three items and instead of putting them in a stack and going to get some more, I paid for that bundle, took it to the car and came back for more. I did this about 4 times and the guy running the sale got more gracious each time.
He was having a spur of the moment sale (not advertised anywhere) because there was an estate sale across the street. Only people he got were the left over folks or maybe they came to him first. He had a good run going with about 5 of us there and I at least took advantage of his "flustered" state and made some good deals. I missed a couple of items because a couple of the others WERE making one big stack, but they were also getting prices from him on each part of the stack, not waiting 'till the end to make one price.
Anyway, a good haul. I spent $65 and when putting it in the spreadsheet am looking at round $500 return, so maybe $400 or so profit. I got DVDs (a lot !), name-brand sub-woofer set with dvd player of same brand, Swiss Army knifes (4 at $1 each !) digital scale with the readout on a separate monitor to be hung on the wall (not down at your feet), etc, etc. A real adrenalin rush to be moving fast in there without knocking over people or spindly china cabinets!