I recently bought a P reg ER 5 with 52,000 on the clock for just £400. It's a bit rough around the edges, but what the hell? It has new tyres, 12 mths MOT and everything works.
I've only done a couple of hundred miles on it, but so far, so good. It's not quite as comfy as the CB5 and doesn't have the Honda's aggressive feel when when I (try to) cane it through the gears, but it's smoother at low revs and will tricle along in top like a four. I read once that it's a CG 125 for grown-ups, in that it's so undemanding to ride and maintain, and I'd agree 100%.
I plan to bung on a Scottoiler and soft luggage, and do some gentle touring round my favourite destination, the Orne district (which is like Somerset with no traffic and rooms for 30-40 euros), and shall report with my appraisal afterwards.
So far the bike's done 58 mpg, but that includes seeing how fast it goes, as you always do with a new bike, so sensible riding will get well over 60. Fortunately it's bike which is fun to ride slow, and 55 mph is just 4,000 rpm. It's the only bike I've had with a totally accurate speedo, and has the very nicely designed clocks off the Zephyr.
I'm trying think of anything bad about this bike and I can't. Some numpty at some point has damaged the inside of the rear drum, and now the lever throbs when you apply the rear brake, or maybe it's an inherent fault of the bike, but the front disc on its own has ample stopping-power.
To sum up the ER 5 is pleasant, yes. Exciting, no. Riding through lines of commuter traffic gives me that smug feeling of having twice as much fun as everyone else for half the money!
Four months since buying my ER 5, and having covered 2000 miles, this bike continues to be thoroughly excellent in all respects apart from one - the seat turns into a wooden plank after 1/2 hour of riding. Solution, a chunky sheepskin (well, acrylic really) folded in half under my buttocks and problem solved! I've since discovered that if you can bear to keep within speed limits, it will return 68 mpg, 200 miles per tank, identical to the much slower & less desirable CB Two-fifty!