Are these windows that you can remove or are they fixed in place? I had the same problem with weak seals/fogged glass.
If you can remove them, take them out and drive them to Del Ray Glass. I want to say I paid about $125 a window. If you bring the windows in on a morning they will measure and you can take them home right away to put in while they get the glass ready. When it is ready, bring the windows back and they will have the glass replaced in a day. This involves a lot of driving back and forth and if the weather is bad you could be in trouble so plan well. Del Ray Glass is kind of a haul, esp since now they’ve moved beyond the beltway down Route 1 (just across from the Lowes/Target shopping center). But they know what they’re doing.
If you can’t remove the windows, (i.e., a fixed pane of glass, typical in top portion of double windows) I don’t know how to DIY. I had the same problem and called Blaine Windows. They will take about a week to come out to give you an estimate (they charge $75, but will credit that to your bill). The quotes I got for my window were (again…I think) about $230-$250. Only problem with them: a week to get them out, a week or so to get you a quote, and then a week or so for them to come back, so you need patience. However, they know what they are doing and you will get it done right. I’ve heard they are pricey but I was too lazy to shop around. I know people who have used WindowPro (just google) and they might be a little cheaper but I think the work is satisfactory.