Hello Ilya,
There are several good responses here, and I think some of them would depend on how large your site is and what types of pages they are. Judging by your URL example below, I'm guessing it is real estate related or at least that you have localized pages in different geographic areas.
You have a few issues here. First, this video might help, but it is sort of outdated and misleading in some ways. There may not be a set limit (i.e. we're only going to index 10k pages) but how much of your site gets indexed, and how often it gets crawled is based largely on the quality of your site (assuming all other factors are there, such as sitemaps and crawlable navigation, etc...). And the quality of your site depends on many, many different factors. Of course the two most important for this discussion would probably be uniqueness/usefulness of the content, and the amount of links the site and sections of the site, as well as the deep pages have.
The more links you can get into those deep pages, the more likely it is that Google is going to crawl more often, and index those pages. You said you "can't" get links into those pages. If you can't get links into them, they probably aren't "quality" and therein lies your problem.
If by "can't" you just mean there isn't enough time in the day for you to build links into ALL of these pages, you can still build links into as many as you can. This will get the bots crawling down to that level of your site more often, and make it more likely that this level of your site will be indexed.
Here is another useful link, although it is dated as well:
http://www.seomoz.org/blog/googles-indexation-cap
Having fresh content (with a fresh "last modified" date) usually does, in my experience, entice Googlebot to come back more often. Does that translate into "indexing" more pages? I don't know. But I do know that having better content and more links into those inner pages does translate into more indexation, and not just for the pages linked to externally, but for that entire section/folder/directory of your site.
Consider user-generated content on those pages if you can. A lot of VERY popular review and realestate sites' deep pages would go unindexed without it.
watch?v=gW7AUnZvSAE