Tilly - don't forget that procedures these days are reversible. If you don't like the effect of the filler, it can be dissolved completely. Example: I had some lip filler done in 2008 by another doctor, and I was perfectly happy with the results for ages, looked really good. Then I lost a load of weight - two stone, and my face was a lot thinner so my lips just looked a little too plump in proportion. I had the old filler totally dissolved and a very small amount of new filler added in carefully once I'd decided where I wanted a little extra volume. So don't think you're stuck with filler!
Steben - filler costs vary massively depending on who does it, what type of filler it is, and obviously how much you have done in what area. Example: I had the vertical lines that run from corner of mouth to chin filled (these appeared when I lost weight) and that was £350. I had my dermotologist (not Tracey, a different doctor who is also lovely) do a course of Vital Light on the crepey areas of my decolletage; there were thin vertical lines running from collarbone to cleavage and it was driving me mental, soooo aging. Five treatments at £250 per treatment. No it's not cheap but oh so worth it to me. At the time I winced at the cost but I can wear scoop-neck or v-neck tops without feeling demoralised about the crepe, so it was worth it. Yes, I am that shallow, alas :-)