"deltic 100" In fairness you didn't specify NWC when you made your comparison but none the less let me give you some statistics and make a few points about the difference between payware routes and community routes.
FIRSTLY though let's remember that the cost of NWC route is because it's a "charity" route and that it's proceeds are going to some unique loco restoration projects. Much of what we can enjoy in the UK in our restored railways is down to charitable contribution and hours of voluntary work. It's the same spirit that brings you the community route discs only the effort is a bit messier

, heavier and it involves "real world" costs. Having visited several railway museums and restored railways in the US I can assure you that even in that comparitively rich country there is little to touch the scale and standard of preservation in this country. We have a huge heritage asset in our preserved railways and it's stock. On my visit to to Strathspey Railway a few days ago there were at least a dozen unique pieces of stock awaiting refurbishment and the guy I met there made me think that if the enthusiasm for these projects was matched by money they'd, like many other preserved railways, would be matching (even beating?) the NRM's standards?
But now to Chris's points.
The huge advantage of including a large stock pack with a route, commercial or freeware, is that you can "set up" the stock included so that it has compatible couplings, brakes and performance. Copyright dictates that stock for commercial routes will be unique and there's no doubt that MT and BATS have bought some outstanding new models to the scene. As Dave has pointed out these are at very small margins of profit.
Freeware has the advantage that authors of existing freeware models will almost always allow use of their models in stock packs for routes. With reskinning and tweaking to the factors I've already mentioned you construct a prototypical pack for the era the route is set in. However this all takes time and there are so many edits required in MSTS's "naming" method within the files that actually allow your model to run in the sim that it's incredibly easy, however carefully you work, to miss something. These are minor edits but can be found by various utilities. Why aren't they found then? Well it takes a massive amount of time to produce a route to current MSTS standards and there are so many aspects to the programming that goes into that too. Even with a large team working on a project they'll have their "real lives" as a priority and only so many man hours they can devote to the project. When Chris talks about "having a rest" .......believe me anyone who's been involved in creating stuff will know exactly what he means.
To give you some idea MEP, which many folk have questioned the release date for, has had well over 80 patches and upgrades in it's development and some of these have required many re-writes of activities, modifications to signalling etc. These mods all have to be retested and hopefully on as many types and specs of machine as possible. Even then stuff gets missed.
There is a world of difference too in some of the modern commercial routes and the sort of track found in many community or period route discs. Modern railways are very simple affairs compared with those of 30-60 years ago. Sidings have vanished track simplified for high speed running etc. The simpler your route's track the less potential for problems. Some commercial add ons have VERY limited amounts of stock too. You pay's your money and you takes your choice.
The most important thing is that whoever the routes author/publisher is they listen to feedback and respond as quickly as possible to correct errors. IMHO Chris couldn't have done better?
In short perfect add-ons for an aged and imperfect bit of software are obviously everyones goal but reality stacks the odds of achieving this against the developer. As long as they fix what can be fixed you can't realistically ask for more.
Geoff