I've been away for a few days and just caught up with the various contributions to this thread since I last saw it.
It's fair to say, I think, for the most part that most people have responded genuinely & fairly as they see things. My original premise that replacement battery prices will ensure that the ebike community will not grow, (it may shrink!) still stands true in my opinion.
Clearly, regardless of what some have to say, there are others who believe as I do that we are being ripped off. It is a captive market once one takes ownership of an electric bike and the market, being small and showing only little year on year growth, is being exploited by many in the business determined to make hay while the sun shines.
There are strategies which could be deployed so that, for example, "old hat" 7 or 8Ah batteries which would suffice for a great many of us could be made available close to cost with nobody in the marketing chain taking a profit. For those who demand the latest, shiniest, one squillion miles per charge offering, they can pay the grossly inflated mark-up to cover the alleged R&D costs. The rest of us might buy a bike with that technology in 5 years time.
Now, I don't get my rocks off reading technical papers on electronics but don't anyone be fooled into believing that battery manufacturers' R&D costs are like NASA's or the major drug companies for they are not. Li-ion technology is not in its infancy; indeed, it is probably nearly exhausted and other forms of portable energy production, harvesting and retention are quite well advanced. The companies who lead the way in the field are not those who supply your car or bike batteries but the massive, global conglomerates who provide non-nuclear electricity and pick up lots of government grants in one form or another worldwide.
I mentioned Toyota previously and Flecc kindly explained that their hybrid Prius doesn't use Li-ion technology. What Flecc omitted to mention is that industry analysts believe that Toyota made a sizeable loss on every Prius made in the first 5 years of production. Toyota were determined to place themselves as the leading player worldwide producing "green" automobiles and had to win over America to do that. They succeeded without going bust and both Toyota and every other player in the hybrid car or electric car market continue to employ the strategy of pricing their vehicles way above what might be perceived as their class competitors. Their batteries last a long time and don't cost a fortune, (relatively) to replace. I'm not aware of a bike maker or seller having adopted that model.
When I was a kid, batteries, whether for a torch or for a car, looked pretty much like the batteries we use for those purposes today. Ok, they've improved a bit but they're still not sophisticated beyond our comprehension so I'd like to hear exactly how much cash has gone into R&D over the last 50 years. Not very much in my view! Equally, portable computer batteries have improved leaps and bounds over the last 10 years while the cost has fallen in real terms.
When the people involved in this tiny industry stop taking such large profits from batteries and accept that batteries are little different from brake blocks, tyres or cables, (I can ride my bike without a battery but wouldn't without tyres or brakes!) then perhaps the market in ebikes will grow, the number of batteries required will increase, more people will get into cycling and (dreams...!) government will move on creating more cycling lanes, traffic-free zones and altering the Highway Code giving precedence & right of way to cyclists everywhere.
It's probably way past time to move on from this thread and this is my last word on it. Don't believe any who suggest the suppliers are really doing us a big favour by selling batteries as cheaply as they do. Either they have a vested interest or they are simply misinformed as to production costs. God forbid that you buy an £8000 economy car only to find that new tyres cost £3000 each from Michelin, the only supplier, and you'll have to replace them every two years!