I think if you're looking for new bikes to hold value, or increase (especially when adjusting for inflation), you are most likely kidding yourself. While Bridgestones are insanely overpriced when compared to other comparable used bikes, they still don't exceed their initial value. This pretty much doesn't happen. One of the few cases I can think of where it did were the Schwinn Krates...which capitalized on nostalgia and unaffordability for most kids. Now that they're grown, they want their Rosebud. As those folks age further, values for them will likely drop...precipitously. As others have said, Surlys aren't much more than mid-range, heavy, mass produced bikes. They fill a niche nicely, but I strongly doubt they'll ever be highly collectible. Frankly the much beloved Cross Check and LHT are no better than bikes of the type made in the 80s at reasonable prices...many would argue less well made. The Surly Karate Monkey I had rode so well that I kept it for a month and sold it as quickly as possible. If you're looking for a post-CF steel bike that is more likely to be collectible, think Lemond.

If you're looking for what will increase in value you need to consider a few factors:

Marketing...you want something that people think highly of...think the BOBs for Bridgestone. Using this idea, I'd be looking at Sachs, Rivendell, Paramount and well regarded custom makers.

Scarcity...this is obvious...supply and demand. If there's a lot of something, it's worth less.

Something associated with great, triumphant championships. Think Trek Madones.

Stuff a 15 year old wanted and couldn't afford. Those high end MTBs will go up in value some day...namely when the kid who wanted a Fisher is having his mid-life crises and seeks rose bud.

I think some of the earlier ti stuff...like Merlins...are going to be worth something some day. Right now they are insanely under valued.