I understand you probably don't work with this type/scale of equipment/network on a regular basis, but the fact is $10k *is* extremely cheap. It's also probably a bit of a bogus number, or at least incorporates a whole lot of stuff beyond the actual connection (not just the cost of the optics, but some of the cost of the blade/chassis, and cost of power and rack space over an X year period, etc). The optics themselves are pretty cheap now - probably no more than $800/side, and with the scale of the large operators it's a good bet they're paying $500/ea for 10g SFPs. Believe me, a network operator of this size sneezes 10g optics without thinking about it - their on-site guys probably play dominoes with the spares.
A little fun math: Let's say for the sake of easy math that the average customer pays $42/month for broadband, or $500/year. Let's say the average lifecycle of a 10g optical link and the associated routers is 3 years, and the single cross-connect costs $10k, spread across those 3 years, for a cost of approximately $3500/yr. So, ignoring the cost of the last-mile infrastructure (partly because the vast majority is in place and has probably been paid off for years), the cable company would have to add 7 customers to pay for each new cross-connect. Again using nice round decimal numbers for the sake of easy math, at a cap of 50mbps per subscriber, you could have 200 customers fully saturating their links before you would saturate the 10gbps cross-connect, assuming ALL customer traffic was being routed that way. So if your first 7 customers paid for the cross-connect, and we're talking about 3-year equipment lifecycles, that leaves just shy of $290k for the ISP to spend on their other infrastructure and overhead.
Summary: I think they'll be just fine, and not need to raise your fees (they probably will raise them anyway, but that's an entirely different discussion).