Hi Kno3,
That Regner engine is a pretty neat design! This is the first time I have seen one. What do they sell for?
Making a two cylinder oscillator for 100 Euro is possible but there will usually be sacrifices that will need to be made to the design to accomplish this. Manufacturers would definitely sell a lot more at that price.
Designing engines for production is always a tricky balance between form, function, etc.. Operating costs for a manufacturer are also a huge concern.
The Regner design for instance does not require any welding from what I can see. The main engine frame is primarily built up from machined plates which probably have the steam passage ways cut into them. This is a smart design because it will require less time to put each engine together and also not require any welding. Welding always adds more procedures and cost to each unit due to the need for fixtures, welding, cleaning, and then assembly. Oh and we must not forget the rejected parts that don't pass the welding procedure.

Form or general appearance is always major concern too. The more visually appealing an engine is, the more likely it is to have more components or trickier to produce components, which will also increase production costs. However this may not always be the case. Most of the smaller oscillators in this size range of these three engines typically have pressed in cylinder covers. This is one method of reducing overall costs. A small problem with this method of sealing off the cylinders which may or may not concern most people is that there is not a easy way to service the piston or piston rings should they need servicing. Typically some engines with pressed in cylinder covers do not use O-rings at all for seals and will instead have small grooves cut around the outside diameter of the piston. These grooves provide a means for collecting oil or water which provides some sort of seal.
Painting can also become a huge undertaking thus increase the end cost. Painting one or two engines is not a problem. Painting a couple of hundred can make one wish for an earlier death especially if there are multiple components that require paint. The amount of prep work (masking off) for painting all these little parts can take up to months. Plating is a much more cost effective means of coating components especially when you think of the labor to profit ratio. However plating is not a traditional type of finish for most steam engines.
Part tolerances can also play a roll in increasing an engine's overall cost. Tighter fitting range of allowable tolerances for engine components can not only increase an engines life span but also its performance. A setback to this can be more parts being rejected and thrown away because they do not meet the stricter required dimensions.
Once you have found a good balance of design between engine performance, life span, overall looks, and a efficient way to produce the product you are left with the most important matter,.....price.
As expensive as these engines can be for consumers, there is almost always very little profit in them for the manufacturer. And even less when they sell to distributors. The smartest way to make up for this is to provide the best possible products at the best possible prices and focus more on volume verses trying to retire off of one or two engine sales. Further cost reductions can be accomplished by producing components in volume and these savings are ultimately reflected in the end price. Unfortunately the kind of volume needed to significantly reduce prices even further can not usually be achieved in such a niche market unless the work is farmed out over seas. So the production focus becomes more based on manufacturing efficiency. We run two shops. One is dedicated to Monahan Steam Models. The other to producing components for other industries. Our company uses some of the most advanced and efficient machining equipment available in the world to produce our models more accurately and more cost effectively. Luckily for us this equipment is used to produce items for other industries, as using this equipment alone for the production of steam engines would have bankrupted us years ago. In fact the fair market value we charge to manufacturer components for other industries on the same equipment typically nets us 3 times that of what we offer each component we make for our steam engine business. So not only does the steam engine market bare less return for labor but also less volume.
We run our company as a serious endeavor since we have huge investment in it, but in the end it is really just for the love of steam engines and getting to meet interesting people like all of you.
The simple answer, and probably what I should have left it at before boring you all is yes, we can produce an engine for 100 Euro but unfortunately it would not look like the Venus, Sapphire or the Cirrus.
Best Regards,
Nick Monahan
P.s. If any of you are in our neighborhood around October the 11 there will be a really great model boat show being held at the San Francisco Model Yacht Club's Lake. This is an bi-annual show and there is always a big turn out of Tugs, Paddlers, and Steamers!