Back in the mists of time, when I was a young man (or the 1990s in other words. In the 1980s it was all about John Menzies) I used to spend far more time than was probably healthy in games shops. After completing my morning paper round on a Saturday, and collecting my wages, which were a princely £15 a week, I would head off to one of my favourite gaming haunts. Chief amongst these during this 16bit heyday was my local 'swap shop' Mega Mania.
Mega Mania operated a simple system: They stocked pre owned SMD/MCD games, which were displayed on price banded shelves (£25 was the most expensive, down to £4 IIRC). You could either purchase a game for the listed price, or swap one you already owned for it. Swapping wasn't straight forward though. If your game was worth more than the game you wanted, the swap was free. If it was the same price, you paid £2.50 (IIRC) to swap it. If it was cheaper, you paid the difference. At least, thats how I remember it working.
I would often spend a good hour or so deciding what games I would get that particular week. Mostly, I swapped games as the cost to me was minimal, which mean't more sweets and drinks for the marathon gaming session to come. Occasionally I would outright buy a game. Happy days.
Another shop I often visited was near to my school. It was a small back street job, which stocked a veritable cornucopia of imported delights. Many a lunch break was spent in there, looking at the cool Japanese box art, and wishing I had a working region convertor cart. Indeed, my most striking memory of this shop was the first time I laid eyes on Splatterhouse 3. I wanted that game sooo bad it hurt. Took me another 10 years before I finally played it.....