For me, the advantage to double hung is that I can open the upper half of the window to improve air circulation (warmer air can vent out the top of the window) or to have the window open some without letting rain in.

Of course having the kind that tilt in for cleaning is a nice bonus. I remember sitting on the sill with my upper body outside to clean the second story windows and have no desire to go back to that!

One disadvantage in the brand that I have (CertainTeed from about 1993) is that if the upper half is open, with the screen in the upper position, bugs can and do come in through a gap that the screen leaves at the bottom. It was designed to work well only with the screen in the bottom position.

Yes, in general single hung will be less expensive, but shop around.

In general wood frame window are warmer than vinyl, but if poorly fitting or poorly constructed or single glazed then replacement is a good call. I have seen old wooden windows refurbished to work well, though.

Wood frame is NOT warmer than vinyl. Certainteed actually made a lower end vinyl window that was kind of flimsy and cheap looking.

Vinyl is a great alternative but it needs to be higher end vinyl.

i would look at Okna Windows, Soft Lite, Sunrise, or even Kensignton. They are all nice looking and not the cheap looking stuff you would find at home depot or lowes.

These higher end offerings will all render much better energy efficiency ratings than wood windows. Pay close attention to air infiltration ratings and structural ratings. Higher end vinyl beats wood in those categories as well.

where are you located?

I think since she says that her 1969 house has the original wood windows, replacing them with vinyl will not look that good, either outside or in. While good-quality vinyl windows have superior performance numbers, and they have come a long way in appearance, they still don't have the aesthetics that might be called for in the OP's house. I live in the Chicago area, and in that harsh climate, my Marvin Ultimates wood-clad double-pane have been great. They cost $$$ though. The OP should check out the Marvin Integrity line which is fiberglass on the outside, and wood on the inside. Better-looking than all vinyl, but less money than wood-clad.

Most wood windows are double hungs that use an insert to stop the top sash from operating, thus a single hung. This makes them more expensive than a double hung.

Single hung windows have a less complex design than double hung, so generally they will cost slightly less. However, you have to factor in other elements such as material (wood is more expensive) and energy saving options (argon or krypton gas, low-e glazing, etc). As others have mentioned, the advantage of the double hung window is extra air ventilation and better convenience for cleaning.

+1 to HomeSealed feedback. I also don't see much of a price delta between the SH vs. DH comparison in those handful of scenarios where a customer has requested it. Also, if you are worried about managing the budget with a SH, wood is probably not the best choice here from a budgetary standpoint. Anything that you get that will approach the cost of a good vinyl window is going to be a very substandard wood window and will likely create issues for you or the next owner down the road.