I agree that Val d'Isère is a much prettier place than Tignes. It's just that most slopes down to the village (which you must take, even to get from one mountain to the next - from Bellevarde to Solaise, for example) are either bumpy or very icy quite early in the day.
The Pierre et Vacances is pretty affordable, but was always fully booked when we strated our search, so I've never been able to find anything for our budget in Val d'Isère (and found a lot in Tignes).
So Val d'Isère is fine by me. But since this apartment building is about the only cheapish place in that village, we have to book well in advance (or else, people who commit later in the year, have to make arrangements for themselves, which can be quite expensive in Val d'Isère). The prices mentioned above is - for me - about the max I want to pay (I'm used to go skiing a few times a year, which is expensive enough, and I spend most of the time outdoors - the apartment is only used for cooking, eating and sleeping).