I spent 3 years washing dishes for the 2 of us in an apartment with no DW. Last fall we got a small countertop unit secondhand for $90 (actually sits next to one of our counters on a little thrifted side table). There's still a lot to wash by hand in our case...large pots/bowls/cookware, wooden utensils and cutting boards, knives...But not having to wipe every inch of every plate to get grease/residue off, or scrub every fork's tines, saves me a surprising amount of time and energy. And that results in greater motivation to take care of it. So: I think as far as getting dishes done, I say it definitely helps; and I happen to believe that from an environmental standpoint it saves water/energy (even if it's *possible* to wash by hand with less water/less hot water, I know I don't, because I always do a running-water rinse or I don't feel my dishes are clean).
As for what this would be worth, I would totally think it's worth a couple hundred (cost of a dishwasher) over the course of years of living in a place. Unfortunately, around here, rentals with DW go for 400-500 more *per month* than places without; I don't think I'd go that far. I would, however, get a countertop or roll-away one sooner if I was in a similar situation again.
Oh, and my parents' DW has racks built to support/accept wine glasses and I think humans have broken more glasses than the machine in the time they've lived there. Obviously, loaded intelligently so a heavy bowl can't become dislodged and whack the fragile glasses. Other aspects of the machine are awkward and they've had complaints about its functionality, so I can't recommend it, but I'm sure it's not the only one out there with a glassware rack!