The question posed seems to be very dependant on ones idea of expensive. Everyone is going to have a different opinion on the matter. For me I don't think its too expensive. I go to concerts that cost more than 3 DLC for 2 hours of entertainment. Hockey games are the same after food and drinks. So for me it worth it for the amount of entertainment it gives me. My music hobby (I'll never be professional) has cost me more in the last 6 years than TSW does. But for someone who say just stays ahead on bills and living expenses it would be expensive to them. And they are not wrong. Really there is no wrong answer.
I still think the main problem with Cardiff is that it is too short. It should be at least double the size with more lines and it could have been interesting. The milage of the network is laughable, no matter what the other issues with it may be. Even if it was excuted perfectly, it´s too short! You can´t tell me routes need to be 1/10 of the normal route length, just because they are in "urban setting". That´s a joke, sorry. Same situation with Mildmay, Goblin (whatever the modern name for it is), Glossip, Manchester Communter and all those other 10-20 mile offerings.
To be fair. That is the entire Goblin (Suffragette) line in comparison to others which are realistically incomplete.
for me when I think of hrs spent on each DLC, and then TSW overall, it aint too bad... I mean, I get some routes/locos as new, but many I have gotten in batches via discounts... it is basically endless gameplay, and I only do timetable mode mostly usually I look at how much I desire a specific piece of content and then I look at the price... sometimes it is like eeh, I can wait till discount (like Stuttgart route or Manchester Commuter), sometimes I buy fresh (like I am looking forward a lot to 805, that will be a day one purchase cos I like modern highspeed trains) and it's not like these DLCs are cheap for me... luckily the DLC dont come that often, so I can plan ahead... or when there is new iteration of TSW (which means three new routes with some deluxe trains as well), I try to save up... if I cant afford it at the moment, I either wait for discount or till I got enough money available... it's not like those DLCs are going to run away
also, while it is not an insignificant amount of money for each DLC, I mean... I dont really spend any money I got available on a lot of things, so if there is a piece of content, I can afford it, usually... not a whole lot to see in cinemas or some other spending thing, so yeah, I can get a DLC from time to time... and I would much rather spend money on this than lets say some vanity piece of clothing or whatever like majority of population does (also, no drinking, smoking or stuff like that )
But it still is a niche product, and an add-on route is a niche within a niche yet requires significant work to make. Some add-ons aren't such good value: many of the DTG routes are almost criminally short (e.g. the GWML, full price for Paddington to Reading, a mere 23 minutes by HST? Just Trains did the route all the way to Bristol for TSC for less money). But others are good value, to mention Just Trains again, the Preston to Carlisle route is definitely worth it: if we take it on "how much did JT have to model", for a 90-odd mile long route, with a lot of detail along the way, I would hazard a guess it's more than in Grand Theft Auto's approximately 80 sq km of scenery, and GTA is a mass appeal game where there are likely at least three orders of magnitude more buyers to pay for those graphics assets. JT had to do just as much work on the assets and placing the assets as the GTA team on making and placing their assets at a minimum, so it's not surprising it costs as much as GTA.
